The first thing we need to address in order to really look at this question is: Why the hell is heat bad for our hair in the first place?
When exposed to heat higher than 130 degrees Celsius (about 265 degrees Fahrenheit) your hair does three displeasing things:
1. Your hair's internal moisture flees your hair.
2. The hair's chromophores, the portion of the hair shaft that absorbs and reflects light, begins to break down.
3. The surface of the hair also breaks down, giving you radial and axial cracking across the hair shaft.
In layman's terms, you end up with dull-looking frizziness that is split-end central. (These effects, by the way, are dramatically worse if you heat-style your hair while it is wet. Because steam is trying to escape the hair, you end up with "bubbling and buckling of the cuticle". Don't do it, guys.)
|I found some split ends in my hair yesterday.|
It may be time for a haircut.
Firstly, are heat protection products effective?
Secondly, if they are effective, what is it that they are actually doing?
1. Are heat protection products effective?Researchers in one study in the Journal of Cosmetic Science analyzed the efficacy of certain polymers and surfactants. They used a curling iron to induce damage under a variety of treatment conditions. Next, they looked for hair surface modification and texture changes in the heat-exposed hair. They also used florescence spectroscopy to analyze the decomposition of tryptophan, an amino acid that breaks down with heat and, in hair, is correlated with pigmentation.
PVP/DMAPA acrylates copolymer (sometimes sold under the trade name Styleze CC-10), Quaternium 70 (sometimes sold under the trade name Ceraphyle 70), and Hydrolyzed wheat protein (sometimes sold under the trade name Hydrotriticum 2000) all had measurable effects. Loss of tryptophan, for example, had a protective effect ranging from 10 to 20% for all three ingredients, even after the shortest amount of heat exposure. Sodium bisulfate was also tested. It showed a 15-23% protective effect after ten minutes of heat exposure, possibly due to its antioxidant effect. Basically: Hooray! This shit is doing it's job.
The researchers also found some evidence suggesting that PVP/DMAPA acrylates copolymer may selectively bind to regions of the hair with damage, reducing the surface damage to the hair. (Quaternium 70, Hydrolyzed wheat protein, and sodium bisulfate failed to help with surface damage, with the latter showing some degree of damage.)
(Cliffnote summary for all you skimmers out there: Quaternium 70 and Hydrolyzed wheat protein--> Good! PVP/DMAPA acrylates copolymer--> Best!)
If you specifically want to ensure that the products you are using contain one of these empirically-supported ingredients, you're just going to have to look at the label. A quick google search shows that the Oscar Blandi Pronto Dry Styling Heat Protect Spray, for example, contains PVP/DMAPA acrylates copolymer. If you're blowdrying curls, the Ouidad Climate Control Heat and Humidity Gel has both PVP/DMAPA acrylates copolymer and hydrolyzed wheat protein. The AG Hair Cosmetics Curl Spray Gel Thermal Setting Spray and the Drybar Hot Toddy Heat Protector Frizz Fighter are other options. Y'all can google this on your own. I believe in you. (Obviously, the higher up in the ingredients list, the more there is, so higher up is preferable.)
According to the International Journal of Cosmetic Science, anything that treats your hair with a conditioner is a big thumbs up. In particular, the authors recommend low-molecular weight conditioners, like cetrimonium bromide, which are more effective at penetrating the hair shaft than other conditioning agents.
2. Why are heat protection products effective?This question is even harder to answer because peer reviewed research demonstrating a concrete protection mechanism just isn't available.
That being said, there are a few strong hypotheses. Some products may coat the hair in a buffering layer, which keeps your heat styling product from overheating the shaft of the hair itself. Some may limit oxidation reactions, which may be responsible for tryptophan-loss.
Either way, your hair protectant spray is probably not placebo water in a bottle, but you may want to check the ingredients (just in case).