Hair fibers have very few side effects. Here we’ll take a look at what side effects hair fibers can cause, what causes them, and what you can do to prevent them. .

Hair Fiber Side Effects: What To Look Out For

Reactions caused by hair fibers are rare, but tend to fall into three groups:

• Itching or redness. Usually traced to a preservative or an artificial dye rather than the fiber itself.
• Irritation on skin that is already inflamed. Anything applied to a flare, a burn, or broken skin can make it worse.
• Eye irritation. Caused by fibers going airborne during application, not by the product sitting on your hair.

Which hair fiber ingredients cause side effects?

Most hair fibers are made from either cotton or wool, but reactions to hair fibers tend to come from other ingredients. This includes preservatives, artificial dyes, ammonium salts, and fragrance.

The FDA names fragrances, preservatives, and dyes among the five classes of ingredient that most commonly cause allergic reactions in cosmetics. And the only way to know what is in a product is to read the label. Here are some ingredients to look out for: 

Who is at risk of side effects from hair fibers?

Some people are more likely to experience side effects from hair fibers. We recommend doing a patch test or consulting a professional if you have:

• Broken skin. Cuts, burns, active flares, and fresh transplant grafts should heal before using hair fibers.
• Known allergies. Check the label against whatever you already react to.
• A sensitive scalp. Patch test on the inside of your forearm and leave it 24 hours before putting anything on your head.

None of this is specific to hair fibers. It is the same care you would take with any product you apply to skin.

How to minimize hair fiber side effects?

Most problems with hair fibers can be reduced by paying attention to the ingredient list, the condition of your scalp, and how you apply the product.

• Choose a simple formula. A shorter ingredient list can make it easier to avoid ingredients that commonly trigger irritation. SureThik Hair Fibers contain four ingredients: keratin, sodium bicarbonate, silica, and mineral iron oxide pigments, with no added fragrance or preservatives
• Check the ingredient list. If you already know that you react to a fragrance, preservative, dye, or other cosmetic ingredient, avoid products that contain it. The FDA lists fragrances, preservatives, and dyes among the common classes of cosmetic allergens.
• Do not apply fibers to broken or inflamed skin. Wait until cuts, burns, active irritation, or fresh transplant sites have healed before applying cosmetic products to the area.
• Test a new product before regular use if you have sensitive skin. Dermatologists recommend applying a small amount to a test area twice a day for 7–10 days and watching for redness, itching, swelling, or other irritation.
• Keep airborne fibers to a minimum. Hold the bottle or applicator close to your hair, use small controlled amounts, and avoid shaking fibers toward your face. Hair fibers are not intended to be inhaled or put in the eyes.
• Wash the product out regularly. Removing fibers before reapplying prevents unnecessary product buildup on the scalp.
• Stop using the product if you develop a reaction. If you develop persistent itching, redness, swelling, burning, or a rash, wash the product off and stop using it until you know what caused the reaction.

Are hair fibers safe?

Yes, hair fibers are generally safe when used as directed. They sit on the hair and scalp temporarily rather than changing how your hair grows.

The main safety considerations are not the fact that they are “hair fibers,” but what the product is made from, the condition of your scalp, and how you apply it. Some people may experience itching, redness, or irritation from ingredients such as fragrance, preservatives, dyes, or other additives. Applying fibers to broken or inflamed skin can also make irritation more likely.

Are keratin hair fibers safe?

Yes, keratin hair fibers are generally safe when used as directed. In fact, keratin and keratin-derived ingredients have been specifically evaluated for cosmetic safety. They were found to be safe under the cosmetic uses and concentrations evaluated.

There is also research on finished keratin hair fibers. In a 90-day study of 40 people using keratin hair fibers, researchers reported no serious adverse effects (and most participants also liked the results!). 

SureThik Hair Fibers use keratin made from Merino wool and contain only four ingredients: keratin, sodium bicarbonate, silica, and mineral iron oxide pigments. They contain no added fragrance or preservatives.

Are hair fibers safe to breathe in?

No, hair fibers are not meant to be inhaled. And while there isn’t research into what happens when you inhale them, what we do know is that the inhalation risk from cosmetic powders depends largely on how small the particles are and how much is inhaled. 

The practical approach is to minimize airborne fibers during application. You can do this by:

• Applying over a sink with the bottle a few inches from your head rather than held high. Try tapping the bottle rather than shaking to control the fibers.
• Shake in short bursts instead of emptying the bottle in one go.
• Consider using a targeted applicator such as SureThik’s patented Hair Fiber Applicator to better control the flow.

Are there positive side effects of hair fibers?

Yes, hair fibers have positive side effects too. Most of what people report has nothing to do with their scalp. Hair fibers tend to provide people with:

• More confidence. In a small study of hair fibers, most users liked the coverage and said it improved their confidence.
  
• More styling freedom. You can part your hair where you want it rather than where it covers best.
• No commitment. No procedure and no daily medication. Fibers wash out at night, so you can change your mind any day.
• Cover while you wait. Transplants and treatments take months to show. Fibers fill the gap in the meantime.

FAQs

Is it safe to use hair fibers every day?

Yes, hair fibers are safe for daily use. Wash them out at the end of each day rather than layering fresh fibers over the previous application. Layering hair fibers can lead to buildup against the scalp.

Does keratin cause side effects?

Keratin itself is not a common allergen. It is the protein your own hair is made of. Reactions to hair fiber products almost always trace to a preservative, dye, or fragrance rather than to the keratin.

Do hair fibers contain harmful chemicals?

All hair fiber products are generally made of cosmetic ingredients that are considered safe when formulated and used appropriately. But that doesn’t mean every ingredient will feel comfortable on every scalp.

Some formulas contain ingredients such as fragrance, preservatives, artificial dyes, or certain salts that can increase the chance of irritation or an allergic reaction in sensitive people. So the more useful question is not whether an ingredient is a “chemical,” but whether your scalp tolerates the specific formula.

Can hair fibers cause an allergic reaction?

Yes, though it is uncommon. A reaction is possible with any cosmetic. If it happens, it is almost always a response to a specific ingredient rather than to keratin, so compare the label to other products you have reacted to.

Can hair fibers irritate your scalp?

Irritation from hair fibers is uncommon and usually traces to a specific ingredient rather than the fibers. Applying over skin that is already inflamed, or layering fresh fibers over the previous day's application without washing, accounts for most issues with irritation. 

Are keratin fibers safer than plant-based fibers?

Neither is automatically safer, because the ingredient list decides it rather than the source material. Our guide to keratin fibers versus cotton fibers covers how the two compare in use.