MOTS-c: the mitochondria-derived peptide explained

A 16-amino-acid peptide encoded inside mitochondrial DNA — a discovery that surprised the field when it was first described in 2015.

TL;DR

• MOTS-c is a 16-amino-acid peptide encoded inside the small genome that mitochondria carry separately from the cell’s main DNA.
• Published research describes MOTS-c as a metabolic regulator that interacts with insulin sensitivity and AMPK signaling, mostly in animal and cell-based models.
• As of 2026, MOTS-c sits on the FDA’s Category 2 list, which means 503A compounding pharmacies are not currently permitted to compound it.

What it is

MOTS-c stands for “mitochondrial open reading frame of the 12S rRNA-c.” That mouthful describes where the peptide comes from: a short DNA sequence tucked inside the mitochondrial genome, not the cell’s main nuclear genome.

A useful image: most cells have a “main library” (nuclear DNA) and a small “back-room library” inside each mitochondrion. Until the last decade, the back-room library was thought to encode only the basic mitochondrial machinery. MOTS-c was one of the first peptides identified that came from that back-room library and acted on the wider system.

How it works

Mitochondria are the cell’s energy plants. MOTS-c appears to act as a small messenger that travels out of mitochondria and onto other tissues — particularly muscle. The most-cited mechanism in the published literature involves AMPK (in plain English: the cell’s “fuel-low” sensor that switches on when energy is scarce). MOTS-c has been described as a regulator of insulin sensitivity and glucose handling in muscle (Lee et al., Cell Metabolism, 2015).

Picture a building’s energy manager phoning the lighting and HVAC crews when usage shifts. MOTS-c plays a similar coordinating role across cell systems, at least in published animal and cell models.

Who asks about it

People come to MOTS-c mostly through longevity and metabolic-health content, often paired with discussion of mitochondrial function in aging.

What the research says

The original characterization paper described MOTS-c’s role in insulin sensitivity and metabolic homeostasis in mouse models. Subsequent work has expanded the picture to include exercise physiology and aging-related metabolic decline (Kim et al., Aging Cell, 2018). The clinical-trial evidence in humans is much smaller than the preclinical record.

What to know before considering it

Compounding access is not stable, and any clinical use requires a licensed clinician evaluation.

The Halftime POV

MOTS-c is a fascinating chapter in the larger story of mitochondrial biology. It is also early. The honest read is “interesting research signal, thin human evidence, restricted access.” Three sentences in their right order.

Related reading:

• MOTS-c: the mitochondria-derived peptide in the literature
• Category 1 vs Category 2 peptides: the access framework
• What is healthspan? The concept and why it matters

FAQ

Q: What is MOTS-c? A: MOTS-c is a 16-amino-acid peptide encoded by a small open reading frame inside mitochondrial DNA. It is one of the first identified mitochondrial-derived peptides. Research describes it as a metabolic regulator that travels from mitochondria to other cellular and systemic targets.

Q: Where does MOTS-c come from in the body? A: MOTS-c is encoded inside the small genome that mitochondria carry separately from the cell’s main DNA. The discovery — first described by the Cohen lab in 2015 — was unusual because mitochondria were thought to encode mostly proteins of their own internal machinery.

Q: Is MOTS-c currently available from compounding pharmacies? A: As of 2026, MOTS-c is on the FDA’s Category 2 list, which means 503A compounding pharmacies are not currently permitted to compound it. The February 2026 HHS announcement proposed returning several Category 2 peptides to Category 1, pending a formal Federal Register notice.

Disclaimer

As of April 2026, MOTS-c is classified by the FDA as Category 2, which means it is not currently available from 503A compounding pharmacies. A February 2026 HHS announcement proposed returning these peptides to Category 1 pending formal FDA Federal Register notice. This article is educational and is not medical advice. Halftime Health only prescribes through licensed clinicians in states where our partner physicians are credentialed.

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Sources

• Lee C, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis. Cell Metabolism, 2015.
• Kim SJ, et al. Mitochondrially derived peptides as novel regulators of metabolism. Aging Cell, 2018.

This article discusses compounds that are currently under FDA Category 2 review (see our FDA categorization explainer). These compounds are not currently part of Halftime Health’s published protocol catalog. This article is provided for educational purposes only and does not constitute medical advice or an offer to sell.