Can niacinamide affect menstruation?

Under normal circumstances, using niacinamide at the recommended dosage does not affect menstruation. However, in rare special cases—such as individual sensitivity or abnormal dosing—it may trigger menstrual fluctuations. If concerned, it is advisable to consult a healthcare provider in advance. The detailed analysis is as follows:

In most cases, when niacinamide is used according to the recommended dose, it typically does not interfere with the menstrual cycle. Its primary actions involve skin metabolism or energy conversion, and it does not directly affect the endocrine system or hormone levels—such as estrogen and progesterone—that regulate menstruation. Most individuals experience no changes in menstrual cycle length or flow while using niacinamide.

Potential effects on menstruation may occur in individuals who are particularly sensitive to niacinamide; even standard doses might indirectly trigger a mild stress response in the body, leading to early or delayed periods. Additionally, long-term use of excessive doses may place extra metabolic burden on the body, potentially disrupting endocrine balance and causing menstrual cycle irregularities. However, such cases are relatively rare in the general population.

If menstrual abnormalities occur during niacinamide use, consider discontinuing the product and observing for 1–2 cycles. If irregularities persist or are accompanied by other symptoms, seek medical advice promptly to evaluate potential endocrine or gynecological issues. Before use, always review the product’s recommended dosage to avoid unintentional overuse.