If you look at the ingredient list of a hair serum or scalp treatment these days, you will come across niacinamide more and more often. The ingredient became popular in skincare products over the past few years and has now found its way into hair products.
But what does niacinamide actually do?
What is niacinamide?
Niacinamide is a form of vitamin B3, also known as nicotinamide. It is a water-soluble vitamin that occurs naturally in foods such as meat, fish, nuts, and legumes. Your body can also produce it from tryptophan, an amino acid.
In skincare, niacinamide has been known for years for its broad range of effects: it strengthens the skin barrier, reduces redness, regulates sebum production, and has anti-inflammatory properties. In hair products, the mechanisms are the same, but applied to the scalp.
What does niacinamide do for your scalp?
The scalp is actually just skin. That sounds logical, but it is often forgotten in the hair care world. Sebaceous glands, hair follicles, the skin barrier—all these structures respond to ingredients that also work in facial care.
Niacinamide has a number of specific effects on the scalp:
- Strengthening the skin barrier — niacinamide increases the production of ceramides in the skin. Ceramides are fats that hold skin cells together and prevent moisture evaporation. A healthy barrier on the scalp means less irritation, less flaking, and a better environment for hair follicles.
- Regulating sebum production — an oily scalp and excessive sebum production can clog hair follicles and trigger inflammation. Niacinamide helps normalize sebum production, which for some people contributes to less follicular clogging.
- Reduction of oxidative stress — free radicals caused by UV radiation, pollution, and stress damage cells on the scalp and can weaken hair follicles. Niacinamide has antioxidant properties and protects cells against oxidative damage.
- Influence on cellular aging — a study published in PMC showed that niacinamide lowers the protein expression of p16 and p21, two markers of cellular aging. Aging cells in the dermal papilla, the part of the hair follicle that drives growth, can slow down hair growth. Niacinamide appears to inhibit that aging.
- Lowering DKK-1 — DKK-1 is a protein that keeps the hair follicle in the resting phase and inhibits growth. Research shows that niacinamide lowers the expression of DKK-1 in human dermal papilla cells, which is theoretically beneficial for hair growth.
Does it actually work for hair loss?
This is where we get honest. Because there is a nuance that you won't find in many product descriptions.
A review article in the International Journal of Dermatology (2020) concluded that, based on existing evidence, topical niacinamide does not directly stimulate hair growth. The effects seen in laboratory settings do not automatically translate to clinically measurable hair growth in humans.
What we do have: a small-scale pilot study in which women with hair loss showed a statistically significant improvement in hair density and hair volume after six months of using a niacinamide preparation, as measured by blinded photo assessment.
One small study, mainly on women. That is not ironclad evidence.
The honest conclusion: niacinamide is not an ingredient that stops hair loss or significantly stimulates hair growth on its own. But it does contribute to a healthier scalp, and that is not an unimportant factor.
The scalp as a foundation for hair growth
This is something that remains underexposed in discussions about hair loss. The focus is almost always on stopping DHT, activating hair follicles, or stimulating blood circulation. Those things are important. But the condition of the scalp itself also plays a role.
An inflamed, dry, or oily scalp provides a worse environment for hair growth. Ingredients that keep the scalp healthy, including niacinamide, are therefore useful as part of a broader approach.
They are not the components that solve everything, but they support the effectiveness of more active ingredients such as Redensyl, Procapil, or caffeine.
Niacinamide in combination with other ingredients
Niacinamide works well with active hair-growth ingredients:
- Caffeine directly stimulates the hair follicle and inhibits DHT at the cellular level. Niacinamide supports the scalp that caffeine acts upon.
- Redensyl and Procapil activate hair follicle cells and extend the growth phase. Niacinamide reduces cellular aging and inflammation that can inhibit that activation.
- Rosemary has proven anti-inflammatory effects on the scalp, through different mechanisms than niacinamide.
Combination products that contain niacinamide alongside proven active ingredients are more useful than products that rely solely on niacinamide. The Hairborn Growth Serum combines a range of active ingredients with supporting components for a complete approach to hair loss.
How do you use niacinamide for your scalp?
If you are using a serum or treatment with niacinamide, there are a few practical points to keep in mind:
- Apply it to a clean scalp. Dirt and sebum reduce the absorption of active ingredients. Preferably use it immediately after washing.
- Massage it in well. Not just for better absorption, but also for blood circulation in the scalp.
- Use it consistently. Sporadic or one-time use makes little sense. Give it at least 8 to 12 weeks before forming a judgment.
- Combine with a complete approach. Nutrition, sleep, and stress management also influence your scalp. Niacinamide is not a replacement for a healthy foundation.
Side effects
Niacinamide is generally well tolerated. Side effects are rare. In some people, high concentrations may cause slight irritation or redness during the first applications. This usually disappears on its own.
Do not confuse niacinamide with niacin (nicotinic acid). Niacin can cause a so-called flushing reaction, a temporary red color and warm sensation of the skin. Niacinamide does not cause that effect.
Conclusion
Niacinamide is not a miracle cure for hair loss. But it is not a useless ingredient, either.
It strengthens the skin barrier, regulates sebum, inhibits cellular aging in the hair follicle, and reduces inflammation on the scalp. These are meaningful contributions, especially as part of a serum that also contains active hair-growth ingredients.
Anyone who buys niacinamide as a standalone solution with the expectation of visible hair growth in eight weeks will be disappointed. Anyone who sees it as a supporting component of a consistent routine is much closer to reality.
Frequently asked questions
Can you keep using niacinamide daily without building up a tolerance?
Yes, niacinamide does not cause tolerance and does not lose its effect with long-term use. It is a stable ingredient that you can continue to use daily for months without any problems. In fact, the supportive effects on the scalp barrier and sebum regulation benefit from consistent, long-term use rather than intermittent use.
Is niacinamide suitable for a sensitive or irritated scalp?
Yes, niacinamide is known precisely as one of the milder active ingredients and is often recommended for sensitive skin, including in facial care. For an irritated scalp, it can even have a soothing effect thanks to its anti-inflammatory properties. In the case of a severely irritated scalp, test on a small area first before applying it to the entire scalp.
Can you combine niacinamide with minoxidil?
Yes, that can be done without any problems. Niacinamide works on the condition of the scalp itself, while Minoxidil works on the hair follicle via vasodilation. There is no known negative interaction between the two, and some people deliberately use a niacinamide serum alongside Minoxidil to limit scalp irritation.
Does niacinamide also help against dandruff?
Because of its sebum-regulating and anti-inflammatory action, niacinamide can potentially contribute to a healthier scalp, but dandruff often has a fungal component that niacinamide does not directly address. For persistent dandruff, a targeted antifungal agent usually works better. Niacinamide can then at most play a supporting role alongside such a treatment.
Is niacinamide also found in regular shampoos, or only in serums?
Niacinamide is now available in both forms, but it stays on the scalp longer in a serum than in a shampoo that you rinse off after a few minutes. For a noticeable effect on the scalp barrier, a leave-on formula such as a serum is the more logical choice, for the same reason that other active substances work better in a serum than in a shampoo.
Can you use too much niacinamide?
Applying it more frequently does not accelerate the effect and primarily increases the chance of slight irritation in people with a sensitive scalp. Follow the recommended frequency on the label, usually once daily. Using more than recommended has no proven extra benefit for the scalp or hair follicle.
Is niacinamide safe to combine with a dermaroller?
Yes, niacinamide is one of the milder ingredients and can perfectly well be used in combination with a dermaroller, provided you follow the same sequence as with other active substances: roll first, then apply the serum once the scalp has calmed down. The anti-inflammatory effect can even contribute to a calmer scalp after rolling.
Does niacinamide work faster on an oily scalp than on a dry scalp?
Niacinamide regulates sebum production, so on a naturally oily scalp, the effect on the sebum balance may be more noticeable than on a dry scalp. On a dry scalp, the added value lies primarily in strengthening the skin barrier. In both cases, the effect is gradual and only noticeable after weeks, not immediately.
Can you use niacinamide if you also take vitamin B3 supplements?
Yes, that can be done without any problems. Niacinamide that you ingest via food or supplements works throughout your entire body through your bloodstream, while topically applied niacinamide acts directly on the scalp. There is no known interaction between the two modes of administration, and many people use them alongside each other without problems.
Is there a difference between niacinamide from a serum and niacinamide from food?
Yes, there is a difference. Niacinamide from food is processed by your body and distributed where it is needed, with little targeted influence on the scalp specifically. Topically applied niacinamide in a serum acts directly on the skin cells of the scalp itself. For a targeted effect on the scalp, topical application is therefore more effective than nutrition alone.
