Can NMN Supplements Cause Headaches?
Based on the available clinical trial evidence, NMN supplementation does not cause headaches and is well-tolerated in healthy adults at doses up to 1250 mg daily.
Safety Evidence from Clinical Trials
The most robust safety data comes from multiple randomized controlled trials examining NMN supplementation in healthy adults:
No headaches reported: A 4-week trial of 1250 mg daily β-NMN in 31 healthy adults (ages 20-65) found no severe adverse events and no changes exceeding normal physiological variations in any clinical parameters 1
Well-tolerated across dose ranges: Clinical trials using doses from 150 mg to 1250 mg daily for 4-12 weeks consistently reported no serious adverse effects, with any minor side effects determined to be independent of NMN supplementation 1, 2
Specific 12-week safety data: A placebo-controlled trial of 250 mg daily NMN for 12 weeks in 30 healthy volunteers showed no abnormalities in physiological or laboratory tests and no obvious adverse effects 3
Intravenous administration safety: Even intravenous NMN administration in 10 healthy volunteers caused no adverse effects on cardiovascular, hepatic, cardiac, pancreatic, or renal markers 4
Important Distinction: Nicotinamide vs. NMN
Critical pitfall to avoid: Do not confuse NMN (nicotinamide mononucleotide) with nicotinamide (also called niacinamide), as they have different side effect profiles:
Nicotinamide can cause headaches: When used therapeutically (such as with tetracyclines for pemphigus vulgaris), nicotinamide causes "flushing and headaches due to vasodilation" 5
NMN does not share this effect: NMN is a metabolite of nicotinamide and is converted to NAD+ through different pathways, without the vasodilatory effects seen with high-dose nicotinamide 1, 3
Dosing Context
The upper limit for nicotinamide is 12.5 mg/kg/day (approximately 900 mg/day for adults), above which adverse effects may occur 5
NMN has been safely studied at doses up to 1250 mg daily without the flushing or headache side effects associated with nicotinamide 1
High interindividual variability exists in NAD+ response to NMN supplementation (coefficient of variation 29.2-113.3%), but this relates to efficacy, not adverse effects 6
Clinical Bottom Line
If a patient reports headaches while taking NMN supplements, investigate alternative causes rather than attributing them to the supplement itself, as clinical trial data spanning doses from 150-1250 mg daily for up to 12 weeks show no association between NMN and headaches 1, 3, 2, 4.