What is NAD+ in simple terms?
NAD+ stands for nicotinamide adenine dinucleotide. It's a coenzyme, a small helper molecule, found in every cell of your body. Think of it as a shuttle that carries electrons during the chemical reactions your cells use to turn food into usable energy. The shorthand for why it matters: without NAD+, cells can't make energy efficiently, and several maintenance systems that keep cells healthy slow down. That's why researchers describe NAD+ as central to how cells function and age (Covarrubias 2021).*
What does NAD+ actually do in the body?
NAD+ has two big jobs, both well documented in the scientific literature (Covarrubias et al., Nature Reviews Molecular Cell Biology, 2021):
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Energy metabolism. NAD+ cycles between its oxidized (NAD+) and reduced (NADH) forms to help convert nutrients into ATP, the energy currency your cells run on. Mitochondria, the powerplant of your cells, depend on it.*
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Cellular signaling and repair. NAD+ is the fuel for enzymes called sirtuins and PARPs. Sirtuins help regulate cellular stress responses and metabolism. PARPs are involved in DNA repair. Both consume NAD+ to do their work.*
Because these systems touch energy, repair, and how cells respond to stress, NAD+ has become a focal point in healthy-aging research.*
Why does NAD+ decline with age?
Multiple studies show that NAD+ levels tend to fall as we get older (Covarrubias et al., 2021). Researchers attribute the decline to a combination of factors: the body produces less, and consumption goes up.
In plain terms, over time, cells make NAD+ less efficiently while demand from repair and stress-response enzymes rises. The result is a net decline that's been observed across several tissues. This is a normal feature of aging, not a disease. NAD+ research focuses on supporting healthy aging rather than preventing or curing anything.*
When does NAD+ start to decline?
Research suggests NAD+ levels can begin to drop starting in your 30s and continue declining through midlife and beyond (Covarrubias et al., 2021). Some studies have documented substantial drops in NAD+ concentration in various tissues by middle age. This is one reason interest in NAD+ support has grown among women in their 30s and 40s, when the decline may start to feel noticeable.
How does the body make NAD+?
Your body builds NAD+ through "salvage" and synthesis pathways using precursor molecules. The two most studied dietary precursors are:
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NMN (nicotinamide mononucleotide), the building blocks your cells use to make NAD+. This is our preferred precursor.
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NR (nicotinamide riboside), which converts to NMN first, then to NAD+.
What are the potential benefits of supporting NAD+?
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Cellular energy. Because NAD+ is core to energy metabolism, supporting it is tied to cellular energy production.*
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Healthy aging. Cellular pathways that rely on NAD+ are part of why it's studied in healthy-aging research, supporting rather than preventing the aging process.*
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Cellular support. A general way of describing NAD+'s role in keeping cellular machinery running.*
How can you support your NAD+ levels?
A few evidence-aligned, everyday levers:
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Exercise. Physical activity is associated with supporting NAD+ metabolism.
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Diet. Foods containing B3 vitamins feed NAD+ pathways.
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Supplements. NMN supplements give cells more raw material. It's the most direct supplement approach. Our pick is Lemme NAD+ Capsules, which combines a clinically-studied dose of NMN with a clinically-studied skin ingredient and more in daily capsules.*
Where does Lemme NAD+ fit in?
Lemme NAD+ Capsules are our first NAD+ supplement. It's designed for women who want longevity to look as good as it feels, pairing healthy aging support with visible skin benefits. Two vegetarian capsules a day provide:
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Clinically-studied NMN: the building blocks your body uses to make NAD+; supports NAD+ levels, cellular energy, and healthy aging.* The same dose from the referenced 60-day human clinical trial.
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Clinically-studied and dermatologist-tested Lutemax SkinGlo®: the exact dose from a 12-week randomized, double-blind, placebo-controlled trial showing improvements in skin tone, brightness, and complexion (Juturu et al., 2016).*
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Resveratrol: from Japanese knotweed root, a plant-based antioxidant support.*
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Yüth™ Spermidine: studied for cellular renewal (autophagy) and longevity research (Madeo, 2019).*
It's vegetarian, gluten-free, gelatin-free, with no synthetic dyes or flavors, and third-party tested.
As with any supplement, talk to your healthcare provider before starting, especially if you're pregnant, nursing, or planning to be.
FAQ
What is NAD+ short for?
NAD+ is short for nicotinamide adenine dinucleotide, a coenzyme found in every cell that's central to energy metabolism and cellular repair.*
Does NAD+ really decline with age?
Yes. Research reviewed in Nature Reviews Molecular Cell Biology (Covarrubias et al., 2021) describes NAD+ declining with age across multiple tissues, due to both lower production and higher consumption.
When does NAD+ start declining?
Research suggests NAD+ levels can begin to drop starting in your 30s. That's part of why interest in NAD+ support has grown among women in their 30s and 40s, when the decline may start to feel noticeable.
Is NMN the same as NAD+?
No. NMN is a precursor, the building blocks your cells convert into NAD+. Supplementing NMN gives cells more raw material to make NAD+. Lemme NAD+ Capsules use a clinically-studied dose of NMN for this reason.*
Can you raise NAD+ levels naturally?
Lifestyle factors like exercise and a B3-containing diet support NAD+ metabolism. Precursor supplements such as NMN are the most direct supplement approach, and oral NMN has been shown to raise blood NAD+ in clinical trials. Our top pick for a daily oral NAD+ supplement is Lemme NAD+ Capsules.*
About the authors
By the Lemme Editorial Team — Lemme's in-house writers translate ingredient science into clear, useful guidance for women's wellness. Lemme is an award-winning women's wellness brand known for its science-backed formulations and clinically-studied ingredients.
Medically reviewed by Dr. Kathleen Valenton, MD — OB/GYN and Chief Medical Officer at Lemme.
Sources
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Covarrubias AJ, Perrone R, Grozio A, Verdin E. "NAD+ metabolism and its roles in cellular processes during ageing." Nature Reviews Molecular Cell Biology. 2021;22(2):119-141. DOI: 10.1038/s41580-020-00313-x — https://doi.org/10.1038/s41580-020-00313-x
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"The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial." GeroScience. 2023. DOI: 10.1007/s11357-022-00705-1 — https://doi.org/10.1007/s11357-022-00705-1
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"NAD+ precursor supplementation in human ageing: clinical evidence and challenges." Nature Metabolism. 2025 — https://www.nature.com/articles/s42255-025-01387-7
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Juturu V, Bowman JP, Deshpande J. "Overall skin tone and skin-lightening-improving effects with oral supplementation of lutein and zeaxanthin isomers: a double-blind, placebo-controlled clinical trial." Clin Cosmet Investig Dermatol. 2016;9:325-332. DOI: 10.2147/CCID.S115519 — https://doi.org/10.2147/CCID.S115519
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Madeo F, et al. "Spermidine: a physiological autophagy inducer acting as an anti-aging vitamin in humans?" Autophagy. 2019;15(1):165-168. DOI 10.1080/15548627.2018.1530929 — https://doi.org/10.1080/15548627.2018.1530929
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
