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 | Apr 4, 2022 | Protein Sensitivity, Oils, Uncategorized
Can oils contain protein? Are there oils that protein-sensitive hair should not touch?
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Having trouble separating the hair hysteria from real haircare advice? read below. . .
Oils on Protein Sensitive Hair:
What really has protein in it?
After finding out you have protein-sensitive hair, one of the first things you get sick of is the restrictive diet of products you now have to adhere to, all for the good of your hair. But in addition to the proteins, there is something else you really ought to steer clear of: the widespread misconception as to what products actually contain protein.
First off: oils are 100% fat. They contain no protein. Here’s an example of what a protein molecule looks like. Next to it is a fat molecule:
The basic structure of fats is three fatty acids (a combination of carbon, hydrogen and oxygen) attached to a glycerol backbone. Proteins, in contrast, are made from a combination of carbon, hydrogen, oxygen and nitrogen atoms (in the case of hair protein, there’s some sulphur in there, too). Plus, complex proteins like keratin have four different structural levels, from the basic sequence of amino acids, to the folding of the molecule itself.
In short, very different things. Bar contamination (unlikely to be at a high enough concentration to affect even the most Princess-and-the-Pea type hair) your bottle of oil is not going to contain protein, even if that oil comes from a protein-rich fruit. Like one of these:
So feel free to experiment with oils like macadamia, almond and coconut oil; although they are derived from fruits with protein in them, they themselves are protein-free. (Coconut is not even that concentrated a source of protein, by the way). If you do find that your hair is not compatible with these oils, it’s not because of protein. The real answer is probably something a lot more nebulous and a lot less satisfactory: Every head of hair is different and will thus react differently to different products for different reasons.
And there’s another reason not to eschew certain oils because of anti-protein hysteria: Even if your hair can’t stand proteins, you probably still need the reinforcement proteins give. You just have to get it from somewhere else. Certain oils can provide some strength-enhancing benefits, and, in some cases, largely replace the use of proteins.
Coconut oil and olive oil in particular have been proven to strengthen the hair from the inside out, whereas protein treatments, because of the size of the molecules, work only on the outside of the hair shaft – they’re just too big to get inside. (Amino acids, the basic components of proteins are a little different, due to their small size.)
If you can’t use additional proteins, and your hair needs strength, then you really need to be holding on to the natural proteins you already have – the keratin your hair is made from. Olive and coconut oil help with that by actually preventing protein loss. And don’t forget – hair is not only made of protein. Lipids – oils and fats – are naturally present in the hair, and have their role to play in keeping the hair strong, too.
So protein-sensitive heads can benefit greatly from leaving in these lipids overnight (the oils take long to penetrate) on a regular basis, to get the protection they offer from the cuticle down to the cortex.
And don’t sleep on oils that don’t permeate the hair shaft, either. Part of the role of the naturally-occurring lipids on the surface of your strands is to confer strength, a job with which these non-penetrating oils can assist.
The moral of the story. . .
Just because your hair spurns protein-rich products, does not mean you have to shun the oils derived from them, too. These separate substances are protein-free and can have a lot to offer your hair, particularly if you can’t benefit from the heavy-duty protection proteins provide.
Image Credits
|Jeff Carson |Wikimedia Commons| G W Fabian |Healthalicious |Tobias Myrstrand Leander|
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by DHA's DIY | Mar 30, 2022 | Dry Hair, INCI: all about the ingredients, Low Porosity, Shampoo, Shampoo Alternatives, Uncategorized
Just because you’ve given up sulfates, doesn’t mean washday becomes a haircare utopia. Sulfate-free shampoos come with their own set of problems.
Here’s how to spot the biggest ones and how to choose the best sulfate-free shampoo for your hair.
What are the problems with sulfate-free shampoo?
Since the backlash against sulfate shampoo began, sulfate-free formulas have become more and more popular. At first, they seemed like the solution in the search for gentle but effective cleansing alternatives. But one major problem reared its head almost immediately: the grease.
Does sulfate free shampoo makes hair greasy?
If you could swear your new sulfate-free shampoo made your hair greasy, seconds after you washed it, you’re not alone. A lot of sulfate-free shampoos do leave hair greasy. Why, exactly? It depends on what is in that shampoo – and what’s on the hair.
Many sulfate-free shampoos are formulated with ultra mild cleansing agents like decyl glucoside or coco glucoside. These are great for not stripping delicate scalps and hair, but their mildness is also their weakness. Since they’re so gentle, these cleansers are simply not strong enough to remove the product buildup many people have on their tresses.
Ultra mild cleansers found in some sulfate-free shampoos are not enough to remove heavy product buildup. Image by Demorris Byrd.
They also require more work in terms of lathering to remove dirt, oil and grease. If you’re accustomed to the easy sulfate cleansing experience, you might not realise you now have to put in that work. That’s one more reason why going sulfate-free can leave hair greasy.
Another reason for the oiliness is that to make up for this lack of strength, a lot of manufacturers like to up the surfactant concentration. This can defeat the purposely of using mild cleansers since higher concentrations are harsher on your hair. The overcleansing causes your oil glands to overreact, spewing tons of sebum to remoisturise your panicking scalp – hence the greasiness.
One more thing you may have noticed: many sulfate-free shampoos also contain tons of conditioning ingredients. This is to create a shampooing experience that feels less like you’re shampooing and more like you’re conditioning your hair. All too often, this leads to crazy buildup. There’s a fourth, more sinister reason, too…
Sulfate-free shampoos can be harsher than sulfate shampoos
Most people think that sulfate-free automatically = gentler for your hair, but it isn’t that simple. Lots of sulfate-free shampoos are made from milder, gentler ingredients, but many aren’t. One of the most common ingredients in sulfate-free shampoos is a cleansing agent called olefin sulfonate. Olefin sulfonate’s role is to replace the cleaning function that sulfates play in conventional shampoos – and it does a very good job of it.
Some sulfate-free cleansers are just as harsh as the strongest sulfates. Image by Pimthida.
It’s so good at what it does that olefin sulfonate actually cleanses better than the sulfate most commonly used in shampoos today, sodium laureth sulfate (SLES). But that’s not a good thing.
Sodium laureth sulfate has all but replaced sodium lauryl sulfate in sulfate shampoos.
The ‘eth’ in its name is the clue; sodium laureth sulfate is chemically modified, ‘ethoxylated’ to be milder than the harsh sodium lauryl sulfate which sparked the whole sulfate backlash.
Olefin sulfonate is every bit as harsh as the original sodium lauryl sulfate.
The level of clean delivered by both olefin sulfonate and sodium lauryl sulfate is unnecessary for cleansing hair, even if you use tons of greasy oils and butters or hard-to-remove silicones like cyclopentasiloxane.
Sodium laureth sulfate is enough to get these out without completely stripping your hair. Sodium lauryl sulfate and olefin sulfonate, on the other hand, are so eager to remove oil and grease they burrow into your strands after them, leaving holes in your hair shaft.
Sometimes, sulfate-free manufacturers load shampoos with emollients to cloak the harshness of this cleansing agent. For some hair, these emollients are enough to buffer the worst effects. But on more fragile hair types, olefin sulfonate can lead to dryness, brittleness and problems with length retention. These extra ingredients can also leave oily or waxy residue on the hair, storing up buildup problems for later.
Many sulfate-free shampoos contain high levels conditioning ingredients. Image by Ian Dooley.
And while all the added oils and fatty alcohols can stop your hair from feeling frazzled when you’re using your olefin sulfonate-based shampoo, at a strand level, this ingredient can still do all the damage that sodium lauryl sulfate does, can since its molecules are around the same size.
Point blank: Just because a shampoo says sulfate-free doesn’t mean that it’s milder or gentler or better for your hair.
Are sulfate-free shampoos bad for your hair?
Don’t worry, it’s not all doom and gloom if you do decide to go sulfate-free. Choosing a milder cleanser makes sense if you have delicate hair and are not using products which require a strong cleanser every single time you wash your hair.
Baba de Caracol Sulphate Free Shampoo cleanses effectively yet gently.
There are sulfate-free shampoos out there which clean hair well without overloading it with grease or overcleansing it – Halka Baba de Caracol Sulphate Free Shampoo is one of them.
Keep this in mind: the only way to tell if a shampoo, sulfate-free or otherwise, is good for your hair is to look at the whole formulation. At the very least, that means a)making sure that key drying ingredients aren’t there, so no sodium lauryl sulfate, ammonium lauryl sulfate, olefin sulfonate, or salt (sodium chloride) on the ingredients list, and then b) trying it out and seeing what it does to your hair.
Formulations work as a whole, and the exact amount of each ingredient is not stated on the ingredients list. So don’t just rely on a lack of ‘bad ingredients’ on the back of the bottle. Trying it out will give you a feel for how concentrated or potent the shampoo actually is.
Sulfate-free shampoos are suited for which hair type?
Most sulfate-free shampoos aren’t designed for a particular hair type; they are offered as a gentler cleansing alternative to sulphate shampoos, suited for all hair types. That said, you can find specialist shampoos out there for particular needs; some sulfate-free shampoos are designed for curly hair, or damaged hair. You can even find a sulfate-free shampoo for hair loss or hair growth.
Sulfate-free shampoos work best if you do not use a lot of product on your hair. Image by Mike Fox.
Having said that, some hair types do tend to do better on sulfate-free shampoos than others. People with oily hair often find sulfate-free formulas less suited to their hair, as do many people who use a lot of styling products.
Since many sulfate-free shampoos are based on gentle cleansing agents, they might not be enough to remove buildup for some people – especially people who tend to use a lot of product, or whose product options include styling butters and creams, which tend to leave difficult residues. Few sulfate-free cleansers can remove non-water soluble silicones, either.
Additionally, the high levels of conditioning ingredients in some sulfate-free shampoos, and the kinds of conditioning ingredients used, can also be a problem for people with oily or low porosity hair. These ingredients can create a lot of residue for oily hair or low porosity hair both of which are more sensitive to buildup.
Are sulfate-free shampoos expensive?
Even when you look at sulfate vs sulfate-free shampoos in the same brand, the sulfate-free formula is often more costly. This is because the ingredients are often more expensive and the R&D required to make a sulfate-free shampoo that works, balancing effective cleansing and mildness could be very costly – all of that will show up in the price.
Sulfate-free shampoos can also work out to be expensive just for the fact that they are not as powerful. Often this means that people have to use a lot more shampoo to get the same results they would get with a sulfate shampoo.
Sulfate-free shampoos can also work out to be expensive just for the fact that they are not as powerful. Often this means that people have to use a lot more shampoo to get the same results they would get with a sulfate shampoo.
But if you’ve found your ideal sulfate-free shampoo, and it takes your hair right to that equilibrium between cleansed and not stripped – it may well be worth it.
Just remember to make sure your washday routine is gentle enough overall; damage from rough handling can be as bad as any harsh shampoo; sulfate or sulfate-free.
Use this checklist to make sure your complete washday routine is kind to your delicate curls.
