> ## Documentation Index > Fetch the complete documentation index at: https://docs.hi-doctor.ai/llms.txt > Use this file to discover all available pages before exploring further. # Niacinamide — barrier support in skin formulas > Niacinamide is the amide of vitamin B3. What it contributes to the compounded rosacea and melasma formulas, and why it is the gentlest active in each of them. Niacinamide, also called nicotinamide, is the amide form of vitamin B3. It is the one ingredient in the compounded dermatology formulas that is not there to attack the condition directly — it is there to make the rest of the formula tolerable, and to add several modest effects that happen to point the same way. ## What it is Active ingredient: **niacinamide**. On this service it appears only as a component of compounded preparations, at three concentrations. In the [rosacea](/library/conditions/rosacea) erythema cream at **4%**, alongside [metronidazole](/library/medicines/metronidazole-topical) 0.75%, micronised [azelaic acid](/library/medicines/azelaic-acid) 10% and allantoin 0.5%. In the rosacea papulopustular gel at **2%**, alongside [ivermectin](/library/medicines/ivermectin-topical) 1% and metronidazole 0.75%. And in the [melasma](/library/conditions/melasma) combination formula at **4%**, alongside [hydroquinone](/library/medicines/hydroquinone) 4%, [tretinoin](/library/medicines/tretinoin) 0.025% and kojic acid 2%. ## How it works Niacinamide is a precursor of nicotinamide adenine dinucleotide, a coenzyme central to cellular energy metabolism and repair. The effects seen in skin follow from several distinct actions rather than one. It increases the synthesis of ceramides and other intercellular lipids in the stratum corneum, which reduces transepidermal water loss. In a formula built around an irritant active, that is the single most useful thing it does. Rather than inhibiting melanin production the way hydroquinone does, it interferes with the transfer of melanosomes from the melanocyte to the surrounding keratinocytes. A different point in the same pathway, which is why the two are combined rather than duplicated. It reduces the release of inflammatory mediators, which is the rationale for its inclusion in both rosacea formulations — where the target is inflammation and the barrier is usually already compromised. It has been associated with a reduction in sebaceous lipid production, which is of some relevance in oily, acne-prone or rosacea-prone skin. ## Why it is in a compounded formula rather than prescribed alone Niacinamide is not a prescription-only medicine and it is widely available in cosmetic products. Its place here is as a component chosen for a specific job inside a formula: buffering the irritation of the active it sits next to, and adding a second, mechanistically different route to the same clinical goal. That is also why the concentration differs between the two rosacea preparations. The erythema cream carries 4%, where barrier support and anti-inflammatory action are most of the point; the papulopustular gel carries 2%, where the heavy lifting is done by ivermectin and metronidazole. A cosmetic niacinamide serum is not a substitute for the compounded formula and not an equivalent of it. The prescription preparation exists because of the prescription-only actives it is combined with — and layering an additional niacinamide product on top of a formula that already contains it is the kind of thing to raise with the reviewing doctor rather than to do quietly. ## What has been reported Niacinamide is among the best-tolerated topical actives in routine use. Reported effects are local and generally mild. | Reported effect | Character | | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | | Mild flushing or warmth | Occasionally reported. It is not the pronounced flush associated with oral nicotinic acid, which is a different molecule | | Stinging or tingling on application | Uncommon and usually transient | | Dryness or itching | Uncommon | | Contact dermatitis | Rare; distinguished from ordinary irritation by intense itch and spread beyond the treated area | In a formula, an irritant reaction is far more likely to be caused by the retinoid, the hydroquinone or the azelaic acid it is combined with than by the niacinamide. That is worth knowing, because it changes what a doctor adjusts if the preparation is not tolerated. ## Realistic timelines Barrier effects are the earliest to appear. Skin usually feels less tight and less reactive before anything visible changes in the condition being treated. The inflammatory contribution in the rosacea formulas runs alongside the metronidazole and ivermectin, and is not separable from them in practice. The pigment contribution in the melasma formula is slow and subtle, and it depends entirely on the area being protected from sunlight. As part of a maintenance preparation, its role is unchanged: keeping the barrier intact so the other actives remain tolerable. ## Who it is not suitable for Anyone with known hypersensitivity to niacinamide or to an excipient. In practice, suitability is decided by the formula as a whole rather than by this component — the pregnancy exclusions on the melasma combination come from the tretinoin and the hydroquinone in it, not from the niacinamide. The reviewing doctor makes that judgement from the questionnaire. ## How Hi-Doctor handles it Compounded preparations are prepared by a pharmacy against a prescription issued after an asynchronous review — no video call, no telephone consultation. You complete the questionnaire for your condition, upload photographs, and a registered doctor decides whether a preparation is appropriate and which one. A prescription is never guaranteed; if one is not issued, the consultation fee is refunded in full. See the [pricing page](/essentials/pricing) for what the consultation fee covers. ## Related reading * [Rosacea](/library/conditions/rosacea) · [melasma](/library/conditions/melasma) * [Metronidazole](/library/medicines/metronidazole-topical) · [ivermectin](/library/medicines/ivermectin-topical) · [hydroquinone](/library/medicines/hydroquinone) · [tretinoin](/library/medicines/tretinoin) · [azelaic acid](/library/medicines/azelaic-acid) * [How to apply a prescription topical](/library/guides/how-to-apply-topicals) * [Side effects of dermatology topicals](/library/guides/side-effects-dermatology) * [Safety and eligibility](/essentials/safety) ## Start a consultation Niacinamide is prescribed here only inside a compounded formula, so the right starting point is the questionnaire for your condition — rosacea below, or the [melasma pathway](/library/conditions/melasma) if pigment is the concern. Declining is a normal outcome. See [what it costs](/essentials/pricing) and [how the review works](/essentials/how-it-works). This page is reference information, not medical advice and not a prescription. Whether a medicine is appropriate for you is decided by a registered doctor after reviewing your consultation.