Longevity Peptide Comparison Guide: Epitalon, NAD+, MOTS-c, SS-31
Published: 2026-08-03 · Last updated: 2026-08-03
The "longevity peptide" category is a marketing shorthand for a diverse set of research compounds studied in aging, mitochondrial, and cellular-senescence literature. This guide compares four of the most-requested — epitalon, NAD+, MOTS-c, and SS-31 — from a Canadian research buyer perspective. Plain English, no dosing advice, no clinical claims. Just what the compounds are, how they compare, and what to know before ordering.
What are the four compounds and how are they related?
Epitalon (also spelled epithalon) is a synthetic tetrapeptide (four amino acids) with a research history in aging and telomere biology literature. It is a small, simple peptide that is relatively cheap and easy to manufacture. It is one of the more approachable entries in this category for a first-time researcher.
NAD+ (nicotinamide adenine dinucleotide) is not actually a peptide — it is a nucleotide coenzyme central to cellular metabolism and energy production. It gets sold through the research peptide supply chain in lyophilised form and studied in aging and mitochondrial research, which is why it lives in this category commercially even though the chemistry is different.
MOTS-c is a mitochondrial-derived peptide with a research history in metabolic and aging contexts. SS-31 (also called elamipretide) is a small peptide that concentrates in mitochondrial membranes; it has research literature in mitochondrial dysfunction and related conditions. Both are more niche than epitalon or NAD+ in terms of Canadian market availability.
Why is NAD+ handling different?
NAD+ is chemically more fragile than most research peptides once it hits solution. It is sensitive to pH, particularly acidic conditions; it is sensitive to elevated temperatures; and it degrades faster than a typical peptide in aqueous solution at room temperature. This is not a manufacturing defect — it is inherent to the molecule.
Practically: reconstitute NAD+ smaller, use faster, and aliquot aggressively. Where you might get a two-to-four-week fridge window on a peptide like BPC-157, NAD+ is better used within a week or two of reconstitution. Freeze-thaw is also harder on it, so aliquoting into single-use tubes at the point of first reconstitution is not optional if you want to preserve the material.
Some suppliers offer NR (nicotinamide riboside) or NMN (nicotinamide mononucleotide) as related but different molecules with better stability profiles. These are precursors to NAD+ in the cellular biosynthesis pathway. They are separate research compounds with different characteristics — do not treat them as substitutes for NAD+ without understanding the difference. The storage guide covers general handling principles.
What about epitalon specifically?
Epitalon is one of the easier research peptides in this category to work with. It is small (four amino acids), it is stable in lyophilised form for a long time, and it reconstitutes cleanly in bacteriostatic water. There is a substantial preclinical research literature going back decades, primarily focused on the pineal gland, telomere biology, and aging models.
Per-mg pricing on epitalon is relatively cheap because it is easy to manufacture. Vial sizes typically run 10 mg or 20 mg. Most Canadian research peptide vendors carry it consistently — supply gaps are less common than with the more niche compounds in this category.
Handling is standard: reconstitute with bacteriostatic water using the process in the reconstitution basics guide, store the reconstituted vial in the fridge, aliquot for longer runs. Nothing exotic required.
What is different about MOTS-c and SS-31?
Both MOTS-c and SS-31 are smaller-market research peptides in the Canadian catalogue. Supply is intermittent — some vendors carry them, some do not, and even the ones that do may have gaps in availability. Both are more expensive per mg than epitalon, partly because of manufacturing complexity and partly because smaller batches drive higher per-unit costs.
MOTS-c is a 16-amino-acid peptide encoded by mitochondrial DNA. The research literature covers metabolic function, exercise biology, and aging-related contexts. SS-31 is a small peptide (four amino acids in its core sequence) with a specific research history in mitochondrial protection and cardiolipin binding.
If your research specifically requires MOTS-c or SS-31, check availability at multiple Canadian vendors before committing to a research plan. The peptides catalogue shows our current stock. If unavailable domestically, cross-border options come with the trade-offs covered in our Canadian vs US comparison.
How do the four compare on evidence and research depth?
NAD+ biology as a molecule is extensively studied across cellular metabolism, aging, DNA repair, and mitochondrial research. That is different from evidence for therapeutic NAD+ supplementation, which is a more variable and less-settled research area. When someone says "NAD+ is well-studied," they usually mean the underlying biology, not the supplementation research.
Epitalon has a substantial Russian and Eastern European research literature going back to the 1980s. Western literature is thinner but present. MOTS-c is a more recent discovery (published around 2015) but has accumulated a real body of literature since. SS-31 has a specific research niche in mitochondrial protection with several clinical trials in that area.
The generic advice: read the actual literature for whatever compound you are planning research around. Do not rely on vendor marketing copy or third-party summaries — go to PubMed and look at the primary papers. This applies to any research peptide, not just the longevity category.
Which should a first-time buyer start with?
Epitalon is the easiest entry point in this category. Cheap, stable, widely available, forgiving of handling mistakes. Reconstitution is standard, storage is standard, and if you make a mistake you have not wasted much money. If your research interest is genuinely in the aging/longevity space, starting here is sensible.
NAD+ is a reasonable second, once you have your reconstitution and aliquoting workflow dialed in. Start with a small vial because you will not use it slowly regardless of how much you buy. MOTS-c and SS-31 are for researchers with specific research questions in those domains — do not buy them speculatively unless you know why.
Standard first-time buyer discipline applies: buy small, verify the CoA, test the vendor, expand from there. The first-time buyer checklist lays out the broader framework, and the CoA verification guide covers the specific step-by-step.
Questions Canadian buyers ask
Is NAD+ actually a peptide?
Technically no — NAD+ is a nucleotide coenzyme, not a peptide. It gets grouped in this category because it is sold and handled through the same research peptide supply chain, in lyophilised vials, and shows up in similar research contexts. The distinction matters when reading literature but not when ordering.
Why is NAD+ so much more fragile than the other three?
NAD+ degrades faster than most peptides once reconstituted. It is sensitive to pH, temperature, and light. A reconstituted NAD+ vial has a shorter fridge window than most research peptides, and freeze-thaw is harder on it. Aliquot small and use fast.
Which of these are actually well-studied?
Epitalon and MOTS-c have substantial preclinical research literature. NAD+ biology (as a molecule) is extensively studied, though therapeutic supplementation research is more variable in quality. SS-31 has a specific research history in mitochondrial biology. All are legitimate research compounds; depth of evidence varies.
Where does Prescott Bio stock these?
Epitalon and NAD+ are typically available in the Canadian catalogue. MOTS-c and SS-31 are more intermittent because they are specialty items with smaller markets. Check current inventory before planning a specific research order.
Are these safe to buy from a research peptide vendor?
They are legitimately-sold research compounds from reputable vendors. The safety and quality questions are the same as for any research peptide: batch-specific CoA, HPLC purity, mass-spec identity, third-party lab. Verify each batch. Do not accept "trust me" as a substitute for a real CoA.