by DHA's DIY | May 8, 2022 | Heat, Transitioning, Hair Straightening
Contrary to popular belief, it is possible to straighten your new growth without burning your relaxed sections or scalding your scalp.
Heat straightening new growth doesn’t have to hurt your newly emerging curls, either, if you know how.
Check these do’s and don’ts . . .
Straightening new growth: A heated transition. . .
As your curly roots start peeking out of your scalp more and more, it might be time to start thinking of ways to get them to blend with your relaxed hair. As well as heatless, curly options which get the two hair types to meet midway, you can sometimes opt for a straight approach to creating some style cohesion. This does come with its own set of rules.
Don’t straighten new growth and relaxed hair at once.
Given the different heat requirements and tolerances, it’s dangerous, not to mention impractical, to attempt the two at once. Instead, apply your heat protectant throughout your hair but focus on getting the roots straight before you move onto the rest of the hair.
The relaxed hair will need a buffer against the heat too, particularly the hair just over the border from the natural part, at the line of demarcation.
Once the roots are done, turn down the dryer or iron (and if it’s an iron, actually wait for it to cool down first) to a lower setting before you tackle the relaxed ends.
You can still work on your hair in sections – just make sure the roots of each particular section are done before you progress onto the relaxed part.
Do stretch your hair before applying direct heat.
To minimise your hair’s exposure to heat, stretch it first either by airdrying it in bantu knots, banding or threadwrapping, or a rollerset under the hood dryer. Since your hair will be straighter from the start, it will require less heat and less tension to straighten, making things easier on you in the short run, as well as safeguarding your tresses in the long run.
Don’t heat straighten your hair more than 2x a month.
Anytime you expose your hair to heat beyond a certain temperature, it is damaging.
Small amounts of damage (i.e., the level of damage that occurs during low frequency heat use, short intervals of exposure to heat, use of heat protectants) are sustainable, and probably not even noticeable on your hair. Overdo it, though, and you’ll soon see the downsides for your hair.
So resist the temptation to fire up the tongs or blowdryer more than twice a month. If you want to use heat more frequently than this, opt for indirect heat, i.e., under a hood dryer, though this will not be as effective on smoothing the roots.
Do use a concentrator nozzle when straightening new growth.
One of the biggest, most damaging errors you can make in trying to heatstyle transitioning hair is not focusing your heat right.
Exposing fragile relaxed hair to a big blast of heat as you try to blowdry curly roots straight is a no-no. You’ll be lucky if you try this approach and the relaxed hair doesn’t fall right off in your hands.
Instead, always use a concentrator nozzle when blowing out your roots and use a mirror (or two) to make sure you’re keeping the dryer pointed right at your roots.
Don’t heat straighten hair under 1.5 inches long.
. . .or less than the diameter of the heat implement you are using, whichever is the greater. For example, with a 2-inch flat iron, do not use it on new growth that is shorter than 2 inches long. Using a blowdryer, the hair needs to be longer than than the diameter of the concentrator nozzle, plus a little bit of extra length to reflect the size of the section that actually gets hit by the heat from the concentr
This is vital to avoid excess heat on the relaxed section of your hair, which could cause it to break off at the line of demarcation; the point where your relaxed and natural hair meet. Breakage at this point is the biggest fear of most transitioners, and widely yet wrongly attributed to the transition itself. In fact, breakage in transition is not inevitable – it only occurs when excess strain is inflicted on the already-weakened relaxed hair.
To be extra safe, leave a 20% margin of error (i.e., make sure you have new growth that is at least 20% longer than your straightening tool) to keep your tresses extra safe.
Do use the lowest workable temperature on your hair.
Don’t think that because your iron goes to 200 degrees that you absolutely have to use that temperature. Your hair does not need to reach molten state to get straight.
Even if your hair is highly resistant, if you stretch it out well, work in small sections and use a good heat protectant you can use your iron without crossing into the highest temperature range.
The best heat protectants will smooth your hair as well as reducing the impact of the heat, since this sliding mechanism prevents any one section of hair from being over exposed to heat),
Do use a heat protectant when straightening new growth.
For blowdrying, make sure you use cetrimonium bromide, cetrimonium chloride, or hydrolysed wheat protein. For flat ironing, use dimethicone. For best results, the first heat protectant should be a leave in, like Lacio Lacio; with a dimethicone-rich serum over the top, your best would be DHA award wining heat protectant atrActiva Shine Drop Serum.
Don’t blowdry your hair from wet.
Blowdrying hair while it is still wet causes heat bubbles on the inside of the strand which eventually burst, shattering the strand. To avoid this, allow your hair to dry in a rollerset first.
You can airdry your set or sit under the dryer (the hood dryer uses indirect heat which is much gentler than the direct heat of the blowdryer or flat iron). This way you get your hair partially straight with less heat before you use the blowdryer or flat iron. Your relaxed hair, already delicate from the chemicals will be spared the extra strain of excessive heat exposure, and your natural curls will start off on a better foot, too.
Drying the hair in rollers beforehand is the method Dominican stylists have tried and tested over decades. The bonus is you get a head of hair that is extra bouncy and smooth, thanks to the spring and silkiness the rollerset infuses.
Check out the DHA guide to creating the perfect rollerset to master this technique to take you through your transition.
Do keep the exposure times low when straightening new growth.
It’s applicable to all hair, but transitioning hair in particular: move through the hair as quickly as you can to avoid overexposure to heat.
If your tool of choice is an iron, keep the number of passes to a minimum – try for two or a maximum of three per section. If your hair refuses to get to bone straight, then don’t try to force it – it will mean breakage.
If you’re using a blowdryer, then practice your roundbrush technique to make sure you can grab and hold a section taut so you only need to hover over it a few times to get it straight. All of this takes practice, so be prepared to spend some time mastering the brush with the blowdryer turned off.
The results. . .
Using these methods, and balancing them out with heatless styles, you can move through your transition with the option of wearing straight looks having its place assured in your stylebook.
Image Credits
|Olivier Lalin |Fromm International|Thowra UK| Naomi Stelrose Photography|
straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth straightening new growth
by DHA's DIY | May 8, 2022 | Dominican Blowout, Heat, Straight Hair, Blowout, Hair Straightening, Silk PRESS
Press reverting? Seven major factors make straightened hair reversion-prone.
Took care of the first three and still have trouble keeping your natural curls stick-straight after a dalliance with the iron or blowdryer?
Check out the final four forces acting against your straightened strands in Part II.
Press reverting: The reasons for reversion. . .
We said it before and we’ll say it again: the reason of reasons for premature reversion is not getting the hair straight enough from the start. This makes it more vulnerable to the humidity in the air, ever acting against it, hoping to turn it back into its natural waves and curls. There are seven factors in particular that play into your hair’s general tendency to go back to its roots. We let you know the first three in Part I, so let’s break down the last ones to press reverting here and now:
Press Reverting Reason #4: You got your hair wet
You grabbed an umbrella, a headwrap and a hat when you caught the forecast of a chance of light showers. You wore a towel over the scarf under your shower cap in the bath. But then you went and put in a product without checking the ingredients.
Many products, even, surprisingly, those designed for heat-straightened hair, contain water – an ingredient which is as anti-straightened hair as it is curl-friendly.
Water causes hydrogen bonds to reform in the hair, and for your heat-straightened strands, those hydrogen bonds mean curls.
When you’re scanning the ingredients list, keep in mind that products with “aqua” on the list contain water. And products with humectants on the list invite water in. If you want your press to survive a few more days, then steer as clear of the humectants (common ones include glycerine, propylene glycol and squalene) as well the water, even if it is “just a little bit” or towards the end of the ingredients list.
Instead, seal water out using products with hydrophobic silicones high up in the list; dimethicone and amodimethicone are a couple of excellent sealants to look out for.
There is a caveat, however: If you live in an area of high humidity, be aware that, regardless of your best efforts, some of the H2O in the water-rich atmosphere will make it into your hair.
This, in turn, means that some degree of reversion is pretty much inevitable, as even the highest quality sealants are somewhat permeable to water. And let’s not forget the fact that, even in low humidity regions, after a while, the moisture in the air will slowly seep into your strands, taking them back into alpha state. If this didn’t happen, presses and blowouts would leave your hair permanently straight.
Press Reverting Reason #5: You didn’t get the hair smooth enough
Even if you have hair that’s a little resistant, you can amp up the straightness by making sure you smooth it out as much as possible during, before, and after the straightening process. Once your hair hits a certain level of exposure to heat, it will show little progress in straightening, even though you turn up the temperature and multiply the passes with the iron or hairdryer.
That makes it important to stretch the hair as much as you can while it’s still pliable. Use smoothing conditioners and deep treatments, try rollersets, and work on improving your brush or iron technique, not forgetting to wrap your hair immediately after straightening.
Press Reverting Reason #6: Your sections were too big
Just as sectioning well ensures you get moisture to every layer, and tangles out of every tress, it also ensure you get every strand straight.
If you make your sections too big, then enough heat simply can’t reach the inner layers of the hair, as the outer strands will have a “shielding” effect, preventing the iron from contacting them.
The combination of tension and the little heat that does make it through might be enough for the hair to look straight. . . at first.
Within a few hours, however, the fact that not all the hair was touched becomes apparent, as underlayers begin to shrink, creating a puffy, press reverting appearance. To prevent, this make your sections as fine as possible – no more than centimetre thick and definitely no wider than the iron.
Press Reverting Reason # 7: Your hair has supernatural resistant strength
If you’ve corrected every one of the common mistakes listed and still find your hair won’t get straight then your hair quite possibly has a very high, natural resistance to heat.
While most virgin hair has some significant level of resistance, persistent resistance, over many instances of straightening, is a characteristic found in quite a few heads of hair.
It might be frustrating mid-ironing, pressing or blowout, but your press reverting is something to celebrate; it means your mane is strong in the face of one of hair’s biggest stressors, a strength that can help you attain longer lengths.
If this is the case, then either take steps to smooth your hair without high heat, or forego heatstyling altogether; after all, a straight look is just one of a zillion styling options for the inherently versatile naturally curly hair.
Whatever you choose to do, don’t force the issue. Even if your hair won’t get as straight as you want it, repeated exposure to high heat, trying to get it to do what it refuses to–stop your hair reverting, will eventually destroy its natural protein structure, leaving you with damaged hair that doesn’t look good, straight or curly.
For more on reasons behind your press reverting, see part one.
Image Credits
| Amandeep Singh Asnapal | Vinoth Chandar |Ashley Webb| Lauren Paulsen | Cambio de Fractal |
by DHA's DIY | May 8, 2022 | Dominican Blowout, Heat, Straight Hair, Hair Straightening, Silk PRESS
Wondering why your blowouts never seem to make it till the next appointment?
Or why your presses peter out well ahead of schedule?
Your hair rapidly reverting is probably due to one of these seven reasons. . .
Reverting: Failed blowouts all have something in common. . .
All of the reasons and rules of unsuccessful presses and blowouts reverting tie into one overarching principle. Call it the law of straightening, whether temporary or permanent, with chemicals or with heat: if you don’t get the hair straight enough, it’s just not gonna stay straight. Here’s breakdown on why you haven’t been getting it straight and why it’s quickly reverting:
Reverting: You put too much product in your hair
So you really wanted to protect your curls before putting them before the fiery blast of the blowdryer. Not willing to leave a stone unturned, you broke out the heat protectant shampoo, treatment, conditioner, and leave in, following up with the blowdry creme, the thermal spritz and a strong dose of straightening balm.
Or, you’re a fan of all things stick-straight and just can’t get over how smooth your hair looks when you run the hot comb over a thick layer of pressing cream.
Either way, you overdid it. In both cases, whether the goal was absolute protection or absolute straightness, your hair was never actually straightened, just momentarily stretched and weighted down by product.
As the product wore off, your curls became less beholden to gravity and started working their way back to wave and cloud formation.
To avoid product getting in the way of successful straightening, limit yourself to one to two leave in heat protectant products.
When you apply, apply only a small amount – i.e., just enough to cover your strands, so you can smooth and protect and still be able to tell when your hair is actually straight. If you use a concentrated protectant e.g., atrActiva Shine Drops Shield Conditioning Leave In Serum, and work it in well, you won’t have to worry about whether you’ve applied enough product as it will be effective with very small amounts.
Reverting: You didn’t go hot enough
Yes, this part is controversial. Too much heat certainly can cause damage; keratin, the protein hair is made from, begins to denature – become permanently deformed – at anywhere from 140-200 degrees Celsius or 210-250 degrees Celsius, depending on the water content and other factors.
Once it’s gone that way, it’s gone; there’s no question of bringing your hair back to its original state or repairing the damage. All should be well, as long as you keep your heatstyling tools well below these temps. The trouble is, on many heads of hair, the hydrogen bonds (the reformable ones that bring you back to curly as soon as water hits your hair) don’t want to let your hair get straight until the heat gets dangerously close to causing permanent damage.
Unfortunately, in this case, if you’ve made sure you’ve covered all the other bases and still have issues, you’ll simply have to make a choice between leaving your hair not-so-straight or taking the hit.
Reverting: Your hair is damaged
So you got your mane shiny and smooth, right from the roots down to just a couple inches away from the tips. Thinking you must have missed a bit, you slide the iron over the ends a couple more times. Nothing happens. You turn up the heat and hit it a few more times. Still nothing.
Your ends won’t go smooth, not because it’s reverting, but because they are damaged beyond repair – either from heat overuse, excessive dryness, tool abuse, or simple, inevitable wear and tear. That is why they won’t straighten again, ever. The only remedy to get your ‘do silky smooth from root to tip is to create new tips – by promptly chopping those worn ones off.
And there’s more. . .
The forces that work against your straightening ambitions are absolutely relentless. Check out Part II on straightening tresses reverting to find out the rest of the seven reasons that make your hair reversion-prone!
Image Credits
| Amandeep Singh Asnapal | Julie Monday |Uneduex | Choo Yut Shing |Helga Weber|
by DHA's DIY | May 2, 2022 | Dominican Blowout, Heat, Straight Hair, Hair Straightening, Silk PRESS, Uncategorized
Scientists have worked out the exact temperature you can straighten your hair at and get your curls back – it’s 185°C.
That temperature is good for up to 50 passes – with perfect curl reversion.
But does curl reversion after heat mean your hair isn’t damaged? Not necessarily – here’s why.
Heat damage: What flat ironing does to your hair
In a groundbreaking study on how heatstyling affects tightly curled hair, scientists measured the difference in curl before and after flat ironing at 220°C (428°F) and 185°C (365°F).
The first article in this series breaks everything down, from how they chose the curl types to how they worked out the safe temperature to straighten curly hair.
Here’s a quick recap: The researchers found that after flat ironing 50 times at 185°C, curls sprang back to their original selves once washed and airdried. At 220°C, that didn’t always happen. In fact, several of the tight curls transformed into bigger curls and even loose waves that were almost straight.
That overall loss of curl indicated the hair was damaged by the higher heat level. Whereas at 185°C, curl reversion – the technical term for when your curls come back looking the same after heat styling – was pretty much reassured.
But they weren’t done.
Heat damage: What temperature is safe to flat iron your hair?
Lack of curl reversion is a strong indication that hair is damaged. But curl reversion doesn’t mean that your hair is not damaged. Remember, even out of the tresses straightened at 220°C, there were some strands that did revert to their natural curl.
To check for actual damage, the researchers had to use some standard laboratory tests.
They took 50 strands from each of the hair tresses they had flat ironed. First they used a tensile apparatus, which applied stress onto the strands until they broke. The break stress – the amount of pulling it took for the strand to break – was used to determine whether the hair’s tensile strength had changed. If it had, that meant the hair was damaged.
For the hair flat ironed at 185°C, nothing had changed. The hair fibres didn’t break any easier than before straightening and they hadn’t lost any of their original stiffness.
But the tensile testing showed that the hair straightened at 220°C had lost its natural stiffness and started to break more easily. Its break stress was less than half of hair that hadn’t been straightened.
Then they broke out the DSC machine – a gadget that scans and analyses heat to detect changes in proteins.
Just like the curl loss and poor tensile strength indicated, the DSC analysis showed that the internal structure of the hair ironed at 220°C was damaged. The equipment revealed that there were fewer bonds in the hair’s molecular framework.
The internal structure of the hair flat ironed at 185°C, though? It was unaffected. Its internal structure was intact.
Why hair straightened at higher temperatures gets heat damaged
When hair is exposed to high temperatures, this causes the hair protein to permanently change shape or denature, like what happens when you cook an egg.
If the heat level gets high enough, it starts to break apart the disulphide bonds and the alpha keratin backbone that give your hair its internal structure.
This doesn’t happen at 185°C because there isn’t enough energy to break those bonds.
Why do looser curls mean your hair is heat damaged?
The disulphide bonds that hold your hair together and give it its natural structure are also responsible for something else – shape memory.
When hair that has been safely heat-straightened gets wet, it returns to its natural curl pattern – that’s because the water activates its shape memory.
That’s what happened to the hair that was flat ironed at 185°C. Because it wasn’t heat damaged, its ability to revert to its natural curl pattern stayed intact. As soon as it got wet, the shape memory kicked in and it curled right back up again.
Heat damaged hair has lost some of its internal structure, which takes away that shape memory. So when it gets wet, the strands are unable to revert to their original curl pattern.
That’s what happened to the hair that was straightened at 220°C. The structural damage from all that heat meant that many of its disulphide bonds were broken.
Without those disulphide bonds – the same bonds that get broken by a relaxer when you chemically straighten your hair – the hair experienced an overall loss of curl.
This is what caused the “shift to lower curl types” or the change from tight curls to loose curls and waves which was observed by the research team.
Avoid heat damage: turn down the heat
So the moral of the story? To avoid frazzled, permanently straightened, heat damaged hair, be cautious with the temperature when you flat iron. Resist the temptation to turn the dial up past 185°C. There are other, better ways to get your hair straighter and smoother.
And remember: the heat protection from staying at 185°C has only been confirmed up to 50 passes – cumulatively. Bear that in mind if you’re a 2+ passes to straighten kinda girl. It all adds up even if you space hair straightening out.
And if you colour your hair, you might want to keep the temperature even lower. Heat damage on dyed hair can change its colour.
If you straightened your hair on max before you saw this post and now wetting won’t bring your curls back, there are some steps you should take before cutting the damage.
If you’re about to blowdry or straighten your hair, or plan on using heat at all in the near future, you can prevent heat damage if you know the maximum safe temperatures for your type of device, your heatstyling method and your hair type.
You can download this FREE Heat Damage Thermometer Guide with the scientifically proven maximum safe temperatures for using heat on different types of hair.
by DHA's DIY | May 2, 2022 | Heat, Hair Straightening
It’s the typical straightening setup.
First you towel your hair dry, then you turn on the blowdryer to get your hair as straight as possible.
But doing it this way could be setting it up for maximum heat damage.
High heat: High temperatures, high stakes. . .
At high temperatures, some damage to the hair’s natural chemical components – surface lipids and amino acids – is inevitable. However, when hair is wet during the heat straightening process, major structural damage also occurs. The increase in structural damage is a major concern because this is the type of damage that changes the physical properties of the hair – reducing tensile strength, increasing breakage and split ends.
Hence the common beauty advice to remove as much water as possible from the hair before blowing it straight, whether by towelling or airdrying.
The problem with this is that, as it dries, hair loses flexibility, making it more difficult to straighten. So most people will pick up the blowdryer after a quick dab with the towel, not wanting to wait and compromise the end results of the blowout.
Trouble is, the other end results are major damage to the hair as the water boils inside the hair shaft, creating bubbles that eventually pop and burst the strand.
But heat straightening hasn’t always been this way. Back in the day, when the hot comb on the stove was the universal straightener for tight curls, hair was always airdried first. And in Dominican salons, the typical straightening method is definitely no upfront interaction with el Blower.
First, you go under the dryer (indirect heat) with your freshly deep conditioned and roller set hair. Only then will stylists let your hair feel the heat of the blowdryer (direct heat). Not only does this restrict the hair’s exposure to heat (extremely important in a hair culture in which heat is regularly used, but long healthy-looking hair a non-negotiable) but it also gets the hair straighter.
Still, despite the benefits, to most people it is counter-intuitive to sit under the dryer or airdry first. Why, after all, would you blowdry hair that is already dry? Well, heat and tension are the main factors in getting hair straight chemical-free, and you still have both of these when you blowdry on dry hair. Plus, the gentle stretching under the less intense, indirect heat of a hood dryer gets the hair that further along the way to straightness, with the rollers adding extra smoothness and bounciness galore.
High heat…And heat damage gets deeper. . .
There’s more: the damaging effect of water reaches all the way into products, too. Recent research analysed hair straightened using water-based heat protectants and those that contained no water at all. The levels of chemical damage were pretty much the same across product type, with both heat protectants offering some degree of shielding from this type of damage.
However, when it came to structural damage – the big dog of damage – the difference was stark. Hair that was straightened with water-based products showed dramatically higher structural damage, leaving it obviously weakened and brittle. Scientists put the results down to the fast evaporation of water that occurs at high temperatures and advised the removal of water from products designed to protect the hair from heat.
High heat: So how can I protect my hair?
As ever, increase your ingredients knowledge and keep a sharp eye on the label. Heat protectant products that contain water (this will include most creamy, lotiony products and even some serums) are not going to give you the heat damage protection they promise if you use them with high heat.
Instead, use your heat protectant leave ins while your hair is still wet, then airdry your hair, or sit under the dryer at a low-to-moderate heat. When it’s time to use the iron or the blowdryer, apply another layer of protection – and keep it completely water-free.
Choose a concentrated silicone based, water-free serum to provide this final line of protection. Make sure it has dimethicone high up on the ingredients list with few other ingredients – many of the additives included in some serums can actually hamper the serum’s ability to protect the hair from heat, and reversion.
While layering your heat protection is good, just making sure you keep those aqua-containing products away from the high temperatures will ensure you make it through your heatstyling session with your strands intact and vibrant.
high heat high heat high heat high heat high heat high heat high heat high heat high heat high heat
Image Credits
|Pulpolux| Jenns Karlsson| Dioburto Photography|
by DHA's DIY | Apr 17, 2022 | Heat, Blowout, Hair Straightening, Silk PRESS
Want to straighten your hair and prevent heat damage, but scared you won’t see your curls again after you flat iron?
Heat damage and curls that won’t revert are the stuff of nightmares when you love your naturally curly hair.
But scientists have figured out the exact temperature setting to straighten curly hair and get curl reversion every time.
Lack of curl reversion = heat damage
How things change. Once upon a time, curl reversion was the enemy. The quicker your curls came back after straightening with irons or a blowdryer the more of a nuisance they were.
Having hair that didn’t revert all the way back after a press or blowout was a good thing. It meant you had successfully ‘heat trained’ your hair or, even better, you had that ‘good hair’ that didn’t nap back up like the less fortunate.
Fast-forward and, thankfully, people are way more educated about their hair. These days, pretty much everyone knows what a lack of curl reversion after straightening is: heat damage.
Telltale signs of heat damage on curly hair: looser curls and thinned out ends. Image by Tubarones Photography.
And, after decades of work from the pioneers of the natural hair movement to undo centuries of miseducation on African hair, natural hair is mainstream.
Nowadays, it’s common for people with naturally curly hair to wear their curls most of the time, even if they dabble in the occasional blowout or silk press.
Pressed or blown out hair has gone from being the main styling option for people who chose not to relax their hair to something some naturals do once or twice a year, as a length check or temporary change of style.
When curly is your default style, “heat-trained” hair with its limp, lifeless curls is no longer an option. Instead, a new ritual has installed itself.
Once the straight look has run its course, it’s time to jump in the shower, douse your hair with water and wait anxiously for that moment of truth:
“Will my curls come back?”
Even a couple of strands that won’t curl back up can cause alarm. Fervent naturals have been known to break out the scissors immediately if their curls don’t pop. Tanisha is one of them.
The last time she overdid it with the flat iron, she realized a deep trim had to happen. “From the way it flopped back on my forehead after the first rinse, I knew it. Once it was dry, I started counting all the crazy half-straight strands. I just went in and cut out the damage.”
After chopping four inches off her fine afro-textured hair, which reaches the middle of her back when straightened, Tanisha says she thinks it was worth it. “Definitely. I spend all this time and money to have healthy hair. I didn’t want the heat damage spreading up through my hair.”
Curl reversion is important to naturals who try to avoid heat damage. Image by Rodolfo Quiros.
A stress-free way to prevent heat damage
But what if it didn’t have to be so stressful? What if you could tell in advance exactly what temperature you could flat iron at, get sleek, straight hair and still be sure your curls would be there after?
Temperature tips for hair straightening are all over the Internet, from professional stylists and bloggers alike. Unfortunately, very little is based on science per se. A lot of the recommended temperatures are very different too, which only adds to the confusion.
But if you’ve been growing your hair heat-free for the past couple of years and want to straighten your curls without heat damage, we’ve got some good news for you.
Can you really heat straighten without damage?
Yes. Scientists have found out exactly what temperature you can safely flat iron your hair at without losing curls.
And guess what? One of those studies focused specifically on tightly curled hair types, which tend to get very little light in the hair science literature – though that is changing.
Working with these hair types allowed researchers to see if the protective benefits of a low temperature setting, observed in another study on looser curly hair, also applied to tightly-coiled hair.
Oh, and in another sign of changing times, this study actually namechecks the natural hair movement, crediting it as the reason women now expect to get their curls back after heat styling.
How they found out the perfect temperature
In this study, researchers looked at the effects of two heat settings: 185 degrees Celsius (365° Fahrenheit) and 220 degrees Celsius (428° Fahrenheit).
Before straightening, they classified the tightly curled hair types, using the L’Oréal hair typing system.
The hair samples chosen were Types V, VI and VII, which roughly correspond to types 3c, 4a and 4b in the Andre Hair System.
Hair types in the curl reversion heat test. Anticlockwise from top: Type V, Type VI and Type VII by Tubarones Photography.
To get an idea of how repeated heat straightening would affect the hair, the team ran straightening irons on each sample at both temperatures 50 times to reflect long-term exposure at each heat level.
Then, they rewet the hair, let it air-dry and waited to see what would happen.
Results: What temperature is safe to straighten your hair?
When they checked the hair over at the end, this is what they found:
- 37.5% of individual hairs ironed at 220°C were unable to revert to their natural curl pattern.
- Overall, only 25% of hair bundle samples exposed to that temperature were damage-free.
- The total number of supercurly Type VI and VII strands fell after straightening at 220°C. At that temperature, there were more type V strands which were the loosest curls in the original sample.
- After 220 degree heat, there were even some type III and IV – wavy and loosely curled hair types like the picture below – that were definitely not present before using the straighteners.
Heat damage turned some tightly curled hair into loose curls and waves. Image by Tubarones Photography
So does curl reversion mean no heat damage?
That strong curl reversion is a good sign for anyone who likes to rock straight hair every once in a while, but wants their curls back once the straight look is done.
On the looks of the hair alone, it seemed like heat damage didn’t happen at 185°C. But that wasn’t enough evidence. Heat damage isn’t always visible to the naked eye, and that’s why curl reversion doesn’t necessarily mean zero heat damage. So what happened when the hair was tested with advanced scientific equipment designed to detect hair damage? It’s all in Part 2, which you can read right here at DHA’s DIY.
prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage prevent heat damage
You can get the list of scientifically proven temperatures it’s safe to use heat on your hair in this guide.
