Vitamin B3

Vitamin B3 is the raw material your body uses to make NAD and NADH. These coenzymes sit at the centre of energy production in every cell. They also support DNA repair and the activity of sirtuins, enzymes linked to cellular ageing.^[1] NAD levels fall with age. That decline is why NAD precursors have become one of the most active areas in supplement research.

If you have heard about niacinamide for skin, NMN for longevity or niacin for cholesterol, this page covers which form nōuxx uses and what the research shows.

Forms of vitamin B3

Vitamin B3 comes in several chemical forms. They behave differently in your body and have different side effect profiles.

Nicotinic acid (niacin) is the original form. At pharmacological doses it is used to lower LDL cholesterol. It also causes the well-known niacin flush. This is a harmless but uncomfortable burning and redness across the face and chest that lasts 15 to 30 minutes.^[1]

Nicotinamide (niacinamide) is the amide form. It feeds the same NAD pathway. It does not cause the flush. It does not lower cholesterol. For nutritional supplementation at NRV-level doses it is the preferred form. This is what nōuxx uses across all three phases.^[1]

Nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are the trendy NAD precursors marketed for longevity. A 2026 randomised trial in 65 healthy adults compared all three. NR and NMN raised circulating NAD over 14 days. Plain nicotinamide produced an acute spike but no sustained rise at the doses tested.^[3] NR and NMN cost roughly 10 to 20 times more per gram.

Inositol hexanicotinate is marketed as no-flush niacin. The evidence that it actually raises NAD is weak.^[1]

nōuxx uses nicotinamide because it covers the full set of EU-authorised vitamin B3 functions at the food-supplement dose. It is well tolerated. No flush.

How much you need

The European Food Safety Authority sets adequate intake at 1.6 mg of niacin equivalents per MJ of energy intake. For a woman eating around 8 MJ per day this works out to roughly 13 mg.^[1] The EU nutrient reference value used on supplement labels is 16 mg.

Vitamin B3 is found in meat, fish, poultry, peanuts, mushrooms and fortified cereals. Your body can also make it from tryptophan. About 60 mg of tryptophan converts to 1 mg of niacin. True deficiency is rare in high-income countries. The classical deficiency disease is pellagra.^[2] nōuxx Cycle Routine contributes 20 mg per phase, 125% of the NRV.

The science on women's health

Skin

The strongest skin evidence for nicotinamide is topical. Topical nicotinamide at 2 to 5% has been shown to improve barrier function and lighten hyperpigmentation. It works by supporting ceramide synthesis in the stratum corneum.^[4] A 2025 randomised trial in 67 women aged 30 to 60 found that a topical niacinamide formulation raised stratum corneum hydration and reduced sebum compared with placebo.^[5]

Oral nicotinamide has the strongest evidence in skin cancer chemoprevention. A 2025 cohort study of 33,822 patients found that 500 mg twice daily was associated with a 14% reduction in non-melanoma skin cancer risk. The reduction reached 54% when nicotinamide was started after a first skin cancer.^[6] This is a much higher dose than nōuxx uses. The relevance of NRV-level oral nicotinamide for everyday skin appearance is more modest.

Energy and metabolism

Vitamin B3 is required to make NAD and NADH. These coenzymes drive the reactions that release energy from carbohydrates, fats and protein. Without enough vitamin B3 those reactions slow down. Tiredness and low mood are early symptoms of deficiency.^[1]

Cellular NAD declines with age. This is the rationale behind the NMN and NR longevity hypothesis. A 2022 trial in midlife adults tested whether nicotinamide riboside could lower systolic blood pressure through this mechanism.^[7] The data on NMN and NR in younger women are still thin. For a woman in her reproductive years the value of vitamin B3 sits in covering the daily requirement so the energy pathway runs smoothly.

EU authorised health claims

Under EU law, niacin is officially authorised to carry the following health claims:

• Niacin contributes to normal energy-yielding metabolism
• Niacin contributes to normal functioning of the nervous system
• Niacin contributes to normal psychological function
• Niacin contributes to the maintenance of normal skin
• Niacin contributes to the maintenance of normal mucous membranes
• Niacin contributes to the reduction of tiredness and fatigue^[2]

References

[1] National Institutes of Health, Office of Dietary Supplements. Niacin: Fact Sheet for Health Professionals. ods.od.nih.gov/factsheets/Niacin-HealthProfessional

[2] Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods. Official Journal of the European Union, 25 May 2012. eur-lex.europa.eu

[3] Christen S, Redeuil K, Goulet L, et al. The differential impact of three different NAD boosters on circulatory NAD and microbial metabolism in humans. Nature Metabolism 2026;8(1):62-73. doi.org/10.1038/s42255-025-01421-8

[4] Boo YC. Mechanistic basis and clinical evidence for the applications of nicotinamide (niacinamide) to control skin aging and pigmentation. Antioxidants 2021;10(8):1315. doi.org/10.3390/antiox10081315

[5] Vergilio MM, Leonardi GR. Topical formulation with niacinamide combined with 5 MHz ultrasound for improving skin ageing: a double-blind, randomised, placebo-controlled clinical study. Current Medicinal Chemistry 2025;32(22):4556-4568. doi.org/10.2174/0109298673325125240813075250

[6] Breglio KF, Knox KM, Hwang J, et al. Nicotinamide for skin cancer chemoprevention. JAMA Dermatology 2025;161(11):1140-1147. doi.org/10.1001/jamadermatol.2025.3238

[7] Freeberg KA, Craighead DH, Martens CR, et al. Nicotinamide riboside supplementation for treating elevated systolic blood pressure and arterial stiffness in midlife and older adults. Frontiers in Cardiovascular Medicine 2022;9:881703. doi.org/10.3389/fcvm.2022.881703