Heat-producing styling tools (hair dryers, straighteners and curling irons) can cause thermal damage to the hair fiber, modifying and degrading hair proteins. Thermo-protectors, as the name suggests, are cosmetic products that protect hair from the heat of styling appliances.
HOW IS HAIR FIBER DEGRADED BY HEAT? HOW TO FORMULATE AN EFFECTIVE HEAT PROTECTION CARE FOR HAIR? WHAT TO OFFER IN A THERMO-PROTECTIVE RANGE? WE EXPLAIN IT ALL.
Protect hair from heat with adapted care products
- July 12, 2023
- 6 minutes of read time
Protect hair from heat with adapted care products
What effect does heat have on the hair fiber?
After regular use of heated tools, you may notice that your hair isn't as shiny, soft and voluminous as it used to be. You may also notice an increase in split ends or excess hair loss every time you take a shower. These are all symptoms of heat-damaged hair. But how can hair be damaged by heat?
Source 1,2
Dehydrated hair after heat exposure
The cortex is the inner part of the hair strands and contains water molecules bound to keratin proteins. Under the effect of heat, water molecules evaporate, modifying the hair's protein structure. High temperatures cause water to dry out rapidly, affecting the structure of each strand and potentially cracking the cuticle, the hair's outer layer, making it more vulnerable to further damage.
In addition, numerous air bubbles can form between the hair cuticles, a product of water evaporation caused by the extreme heat of our appliances and leading to hair weakening to the point of possible breakage.
Drying out the scalp can also lead to skin imbalance, resulting in dryness, flaking and itching.
Modification of hair structure due to heat exposure
High levels of heat or prolonged heat have a direct effect on hair structure at the molecular level, and the damage caused to the hair is cumulative as there are no growing cells in the hair. Above 140°C, structural changes are profound and irreversible3.
Hair is made up of a protein called keratin. Hair keratin has a natural twist called the alpha helix. Temperatures above 150°C transform ⍺ keratin into β keratin, ultimately weakening the hair, which loses elasticity and is more susceptible to damage. Heat above 230°C begins to burn the hair and cause the disulfide bridges - the covalent chemical bonds that give hair its elasticity and strength, and help hold its shape in place - to break down.
Heat responsible of the degradation of hair quality
Heat damage can also lead to oxidation of the pigments in the hair, whether natural or dyed. The result is discolored color, especially when hair is highly porous.
What's more, heat styling opens the cuticle (the outer layer of the hair shaft), increasing friction between strands and making hair more difficult to style, further damaging it under stress.
Damaged hair is rough, dry, dull and frizzy. It loses its natural shine because the cuticles, which give it its shine, have been damaged. Heat-damaged curly hair can look limp and curls may not hold their shape, while straight hair may not look as smooth.
Why use a heat-protective hair care product?
Hair can't regenerate once it's been damaged, so it's important to protect it to keep it healthy and shiny. Designed to reduce the negative effects of heat from our styling appliances, thermo-protective treatments work like an anti-heat shield, depositing a film on the surface of the hair to limit the aggressiveness of heat and distribute it more evenly over the hair fiber. As a result, hair heats up more gradually and evenly, with less damage.
Most of today's thermal protectors also contain active care ingredients to preserve hair moisture, strengthen it and facilitate styling. These are known as multi-purpose thermo-protectors.
In spray, serum or cream form, apply to slightly damp hair before blow-drying, or to dry hair before straightening or curling. It is applied in sections to the hair and then distributed evenly along the length of each strand with a comb.
How to formulate an optimal care product to protect hair from heat?
A good heat protection product should help smooth and protect the hair cuticle, as well as effectively retain its natural moisture.
Film-forming effect, protecting the hair fiber from heat
As we've seen, heat protectants work by forming a protective film around the hair. Generally speaking, these cosmetics contain a lot of silicones. However, given the recent controversy surrounding silicones, many brands are looking to replace them.
Highly viscous, like dimethiconol, EMOGREEN™ HP 40 has very interesting properties for replacing dimethiconol-based blends, as it is biodegradable and 100% natural. Thermal protection tests, carried out on healthy hair braids with the pure raw material and with a hair serum containing 3% EMOGREEN™ HP 40 versus DMD, were performed and a significant gain in protection of the hair's internal keratin structure was observed of +38% and +22% respectively. Thanks to its film-forming properties, performance between EMOGREEN™ HP 40 and DMD is comparable.
Active ingredients for skincare benefits after heat exposure
The multifunctional heat protection products are all the rage. They can contain proteins that help strengthen hair structure, further reducing the risk of heat damage.
Rich in vitamins and essential fatty acids, vegetable oils provide nourishment and repair for dry hair or to combat split ends and breakage. These products also contain moisturizing active ingredients. They may contain proteins to help strengthen hair structure, further reducing the risk of thermal damage.
XYLISHINE™ is a bio-inspired moisturizing active, derived from a combination of biosourced sugars sourced mainly from wood and the Pelvetia canaliculata algae. It intensely and deeply moisturizes damaged hair: up to +30%! It helps control water flow by trapping moisture in the hair and closing cuticle scales, which are effective barriers against dehydration.
Perfect smoothing serum (EU07716)
Other tips in a hair routine to protect against heat
Offer a scalp scrub
By caring for your scalp, you'll create a healthy base for the hair protector to be even more effective. An exfoliating scrub as part of your routine, once a week, will remove dead skin or product build-up that makes hair dull and limp. Massaging the scalp will promote good blood circulation.
Include a hair mask helping the protection of hair fiber from heat
Used once a week, a nourishing mask will strengthen your hair and give a little boost to the effectiveness of the heat protector.
Advising appropriate drying to protect hair from heat
Solutions exist to reduce heat damage during styling, such as the indirect heat of heated caps or heated helmets. Alternating between blow-drying and air-drying can also help preserve hair, as can using low-temperature irons. Choosing the right heaters (ionization, care integrated into the ceramic coating, etc.) and knowing how to use them (temperature, distance and drying time) can be very helpful.
Cosmetics brands can provide advice and tutorials for their customers.
As you can see from this article, it's essential to educate consumers about the damaging effects of heat on their hair, and to offer them judiciously formulated heat-protection products. A range of nutritive, film-forming and repairing products makes sense to meet the daily needs of heated styling appliance enthusiasts.
To remember
- The heat of heating appliances irreversibly damages the hair fiber
- Care products against heat protect hair from heat-related aggressions thanks to their film-forming properties
- It is possible to formulate a routine to help consumers protect their hair and scalp
Sources
1 Curlsmith
2 Kingshow international
3Influences of thermal variations on hair structure, M. F. BORIES*, M. C. MARTINI, M. F. BOBlN and J. COTTE, 1983