NAD+ vs MOTS-c: a coenzyme and a mitochondrial peptide compared

The short version

NAD+ and MOTS-c are often bought together and discussed together, but they are entirely different kinds of molecule. NAD+ is a small dinucleotide coenzyme present in every cell, required by hundreds of enzymes and consumed by a few important ones. MOTS-c is a 16-residue peptide encoded in mitochondrial DNA, discovered in 2015, whose proposed actions run through the energy-sensing kinase AMPK. What links them is the question they are used to ask: how cells sense and manage their energy state, and how that changes with age and metabolic stress.

Both are supplied by BuyUK Peptides as research chemicals for in-vitro laboratory use only.

What each one is

How the literature describes NAD+

NAD+ has two roles. As a redox cofactor it shuttles electrons between hundreds of dehydrogenases and is regenerated rather than used up. As a substrate it is consumed: the sirtuins use it to remove acyl groups from proteins, the PARPs to build poly(ADP-ribose) at sites of DNA damage, and CD38 and CD157 to make signalling molecules, releasing nicotinamide each time [1, 2]. The field's recent growth rests on the observation that tissue NAD+ falls with age [3] and on work identifying CD38 as a major driver of that decline [4].

An important caution for anyone reading the human literature: most of it concerns the precursors nicotinamide riboside and nicotinamide mononucleotide, not the dinucleotide itself [5, 6]. Extracellular NAD+ is largely broken down before it enters cells. For in-vitro work, the direct uses of the dinucleotide are as a cofactor in enzyme assays, a substrate in sirtuin, PARP and CD38 assays, and an analytical standard.

How the literature describes MOTS-c

MOTS-c was reported by Lee and colleagues in 2015 as a peptide encoded by a short open reading frame inside the mitochondrial 12S rRNA gene [7]. In their cell and mouse experiments it altered the folate–methionine cycle and purine synthesis, raising levels of AICAR, an endogenous activator of AMPK, and improved insulin sensitivity in mice on a high-fat diet. Later work from the same group reported that under metabolic stress the peptide moves into the nucleus and influences the expression of nuclear stress-response genes [8], and that circulating and muscle levels rise with exercise [9]. It has no identified cell-surface receptor, and the literature remains concentrated in a small number of laboratories [10].

Where they meet

AMPK and the sirtuins are the two best-studied energy sensors in the cell, and they influence one another: AMPK activation tends to raise NAD+ availability, and sirtuin activity feeds back on AMPK signalling. A programme studying how cells respond to nutrient stress, mitochondrial dysfunction or ageing may therefore use MOTS-c as a way to engage the AMPK side and NAD+ to supply or measure the sirtuin side. That shared territory is the reason the two appear together. It is not evidence that combining them does anything in particular; no published study we have found tests them together.

UK and anti-doping status

Neither is a licensed medicine in the UK or a controlled drug. NAD+ is a naturally occurring metabolite and a standard biochemical reagent; the precursors NR and NMN are a separate regulatory matter. Both are supplied here as research chemicals for in-vitro laboratory use under the Terms of Sale. In sport they differ: NAD+ is not on the WADA Prohibited List, while MOTS-c is named under section S4 as an example of an AMPK activator and is prohibited at all times [11].

Handling at the bench

They are handled quite differently. NAD+ is a hygroscopic powder supplied in a large quantity; keep it sealed, dry and cold, weigh it quickly, and make fresh solutions in neutral buffer, because NAD+ is unstable in alkaline solution and degrades over days at room temperature. MOTS-c is a lyophilised peptide; it contains two methionines and a tryptophan, so solutions should be kept cold and protected from light and air, used within a few weeks or aliquoted and frozen. Choosing a reconstitution solvent and the storage and stability guide cover both.

What to look for on the certificate

For NAD+, purity by HPLC with UV detection at 260 nm, ideally showing the β-anomer and quantifying the reduced form (NADH, which also absorbs at 340 nm) and breakdown products such as nicotinamide and ADP-ribose. Mass spectrometry should show the protonated molecule at m/z 664.1, from a monoisotopic mass of 663.1. For MOTS-c, RP-HPLC purity of 98 per cent or above and a deconvoluted mass of about 2,174.6 Da; watch for oxidation products at plus 16 and plus 32 Da from the two methionines.

Which to choose

For enzyme assays, redox chemistry or sirtuin, PARP and CD38 work, NAD+ is the reagent. For questions about mitochondrial-derived peptides, AMPK activation by an endogenous peptide, or retrograde signalling from mitochondria to nucleus, MOTS-c is the tool. Full accounts are in the monographs for NAD+ and MOTS-c; SS-31 and 5-Amino-1MQ complete the mitochondrial class.

References

1. Houtkooper RH, Cantó C, Wanders RJ, Auwerx J. The secret life of NAD+: an old metabolite controlling new metabolic signaling pathways. Endocrine Reviews. 2010;31(2):194–223. doi:10.1210/er.2009-0026.
2. 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.
3. Massudi H, Grant R, Braidy N, et al. Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS ONE. 2012;7(7):e42357. doi:10.1371/journal.pone.0042357.
4. Camacho-Pereira J, Tarragó MG, Chini CCS, et al. CD38 dictates age-related NAD decline and mitochondrial dysfunction through an SIRT3-dependent mechanism. Cell Metabolism. 2016;23(6):1127–1139. doi:10.1016/j.cmet.2016.05.006.
5. Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224–1229. doi:10.1126/science.abe9985.
6. Rajman L, Chwalek K, Sinclair DA. Therapeutic potential of NAD-boosting molecules: the in vivo evidence. Cell Metabolism. 2018;27(3):529–547. doi:10.1016/j.cmet.2018.02.011.
7. Lee C, Zeng J, Drew BG, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metabolism. 2015;21(3):443–454. doi:10.1016/j.cmet.2015.02.009. PMID 25738459.
8. Kim KH, Son JM, Benayoun BA, Lee C. The mitochondrial-encoded peptide MOTS-c translocates to the nucleus to regulate nuclear gene expression in response to metabolic stress. Cell Metabolism. 2018;28(3):516–524.e7. doi:10.1016/j.cmet.2018.06.008. PMID 29983246.
9. Reynolds JC, Lai RW, Woodhead JST, et al. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nature Communications. 2021;12(1):470. doi:10.1038/s41467-020-20790-0. PMID 33473109.
10. Merry TL, Chan A, Woodhead JST, et al. Mitochondrial-derived peptides in energy metabolism. American Journal of Physiology-Endocrinology and Metabolism. 2020;319(4):E659–E666. doi:10.1152/ajpendo.00249.2020. PMID 32776825.
11. World Anti-Doping Agency. Summary of Major Modifications and Explanatory Notes to the 2025 Prohibited List; and UK Anti-Doping. 2025 Prohibited List: Summary of Changes. Both published 2024. ukad.org.uk.

This monograph summarises the published literature for laboratory researchers. It is not medical advice, and nothing on this site is for human or veterinary use.