NAD+, NMN, and Egg Quality: What the Research Actually Supports

If you've read about egg quality online, you've probably seen NMN or NAD+ described as a way to "turn back the clock" on your ovaries. The excitement comes from real, well-designed studies published in serious journals. The catch is that those studies were in mice. Here's what was actually shown, where the human evidence stands, and the questions worth asking before you spend money on it.

Contents

• NAD+, NMN and the egg-aging idea
• The mouse studies
• What we have in humans
• Why mouse doses don't translate
• What the FDA's 2025 decision does and doesn't mean
• Where niacin fits in
• If you're considering it

NAD+, NMN and the egg-aging idea

NAD+ is a molecule every cell uses to run its energy metabolism and to power enzymes that maintain and repair cells. Your body makes it from several building blocks, including niacin (vitamin B3), nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN). NMN and NR are sold as supplements on the theory that giving the body more raw material raises NAD+.

The fertility idea is straightforward. Egg quality declines with age. In a landmark 2020 paper, researchers reported that the loss of oocyte quality with age is accompanied by falling NAD+ levels. If falling NAD+ is part of the problem, the reasoning goes, restoring it might help. That's a reasonable hypothesis. Whether it works in women is a separate question, and it hasn't been answered yet.

The mouse studies

Two studies published in Cell Reports in 2020 drive most of the interest.

These are careful studies, and the authors of the first one concluded that restoring NAD+ late in life "may be an opportunity" to rescue female reproductive function in mammals. Note the word may. Both papers report mouse data only.

In 2025, a systematic review in the Journal of Assisted Reproduction and Genetics pulled together the preclinical NMN research on egg quality. It included seven studies, in mice, pigs and cows, six of them from a single country. The authors found NMN "consistently" improved egg and ovarian function in those models, but also noted that "its effects are not universally observed," that methods varied widely (injections, oral dosing and adding NMN to eggs in a dish), and that animal reproductive biology may not translate to humans. Their bottom line: "Standardised protocols and clinical trials are needed."

What we have in humans

Here's the full human picture for NAD+ boosters and egg quality as of this writing:

• No published human trials of oral NMN for egg quality or IVF outcomes. The 2025 systematic review found none. It described early human NMN research as mainly about safety, such as a study in which a single oral dose up to 500 mg was tolerated by healthy men and raised NAD+ levels.
• A lab study on donated human eggs, using NADH rather than NMN. A 2025 pilot study in Frontiers in Endocrinology added NADH (a related molecule) to immature eggs left over from IVF cycles, in the lab, and reported better maturation rates. That's eggs in a dish, not a supplement anyone swallowed, and the authors said prospective randomized trials are needed before clinical use.
• Registered trials. At least one trial testing NMN and embryo development in IVF is registered on ClinicalTrials.gov. We did not find published results.

That's it. There's no human evidence yet that taking NMN or NR before or during fertility treatment improves egg quality, embryo quality, pregnancy rates or live births. There's also no evidence that it's safe to take around conception or in early pregnancy, because nobody has studied that.

Why mouse doses don't translate

One practical reason animal results can mislead is dose. The 2025 review notes that the animal studies used 200 to 500 mg of NMN per kilogram of body weight per day. Using a standard body-surface-area conversion, the authors estimated that about 300 mg/kg/day in mice corresponds to roughly 24 mg/kg/day in humans. For a 65 kg person, that works out to over 1.5 grams a day, far beyond any dose that has been studied for safety in reproduction.

That doesn't mean a higher dose would work, or that a lower dose wouldn't. It means the doses that changed mouse eggs have no tested human equivalent, and long-term human safety at those levels is, in the review authors' words, unclear.

What the FDA's 2025 decision does and doesn't mean

NMN's legal status has changed twice. In November 2022, the FDA said NMN couldn't be sold as a dietary supplement because it had been investigated as a drug. After a citizen petition and a lawsuit from supplement industry groups, the FDA reversed course in September 2025, concluding that NMN is not excluded from the definition of a dietary supplement.

That decision was about the legal definition of a supplement. It didn't address safety or effectiveness for anything, including fertility. Supplements aren't reviewed by the FDA for safety or efficacy before they're sold, so "legal to sell" and "shown to help your eggs" are completely different claims. You may still see older sources, including some government fact sheets, describing NMN as not legally marketable; that reflects the 2022 position.

Where niacin fits in

Niacin is the familiar vitamin form of an NAD+ precursor, and you're likely already getting it. The NIH lists the RDA as 14 mg a day for adult women, 16 mg for men and 18 mg in pregnancy. Chicken, turkey, salmon and canned light tuna are among the top sources in the NIH's table.

There's a Tolerable Upper Intake Level of 35 mg a day for supplemental niacin in adults, including in pregnancy, and the NIH says it applies to nicotinamide as well as nicotinic acid. The NIH also notes that NMN and NR aren't marketed or labeled as niacin sources, so they don't show up in that math. If you take a prenatal, a B-complex and an NAD+ product, put all three on the table at your next appointment.

If you're considering it

It's understandable to want to do something about egg quality, especially after a low AMH result or a hard IVF cycle. Before adding NMN, NR or any NAD+ product, go through these questions with your fertility clinician:

1. What would we expect it to do? Be specific. There are no human data showing better egg numbers, embryo quality or pregnancy rates.
2. When would I stop? Pregnancy safety is unstudied. Decide in advance whether you'd stop at ovulation, embryo transfer or a positive test.
3. Does it interact with my treatment? Your clinic should know about anything you take during stimulation.
4. What's in the bottle? Supplement quality varies, and certification seals verify contents, not benefit. Our protein powder guide explains what NSF and USP marks actually check.
5. Is this money better spent elsewhere? Ask your clinician which tests or treatments have known value in your situation before paying for something unproven.

Our supplement list for doctor review is designed to make that conversation quick. If you want to understand the differences between NMN, NR and other NAD+ precursors in general (not fertility-specific), NADvsNMN.com compares the forms and the underlying science.

NAD+ isn't the only "rejuvenation" approach marketed to people worried about egg quality. ConceiveGuide covers two clinical options with their own evidence debates: PRP ovarian rejuvenation and growth hormone for poor responders in IVF.

Sources

• Bertoldo MJ, Listijono DR, Ho W-HJ, et al. NAD+ repletion rescues female fertility during reproductive aging. Cell Reports. 2020;30(6):1670–1681.e7. DOAJ
• Miao Y, Cui Z, Gao Q, Rui R, Xiong B. Nicotinamide mononucleotide supplementation reverses the declining quality of maternally aged oocytes. Cell Reports. 2020;32(5):107987. DOAJ
• Noh H, Sen Gupta S, Seshadri S, Viñals Gonzalez X. NMN supplementation as a strategy to improve oocyte quality: a systematic review and transcriptomic analysis. J Assist Reprod Genet. 2025. UCL Discovery (PDF)
• Zhang Q, Yang H, Yang D, et al. NADH supplementation improves human oocyte maturation and developmental competence of resulting embryos in controlled ovarian hyperstimulation cycles: a pilot study. Front Endocrinol. 2025;16. frontiersin.org
• ClinicalTrials.gov. NCT06629636: Investigate the Efficacy of Using NMN to Improve Embryo Development Capacity. clinicaltrials.gov
• NutraIngredients. FDA declares NMN lawful in dietary supplements (September 30, 2025). nutraingredients.com
• NIH Office of Dietary Supplements. Niacin: Fact Sheet for Health Professionals. ods.od.nih.gov