Peptides and NAD+ in 2026: Separating the Hype From the Evidence

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Few categories in longevity medicine have grown as fast — or attracted as much scrutiny — as peptides and NAD+ therapies. Demand for both is real and growing. So is the gap between how confidently they're marketed and how settled the underlying science actually is. This is an attempt at an honest accounting, not a sales pitch.

Peptides: A Genuinely Broad Category

"Peptides" isn't one thing — it covers dozens of distinct compounds marketed for recovery, metabolic health, tissue repair, and cognitive performance, delivered sublingually, by injection, or orally. Some, like specific growth-hormone secretagogues, have a reasonable evidence base for particular, narrow indications. Others are being marketed for benefits well beyond what any published research actually supports. The category-level hype doesn't apply evenly to every compound in it, which is exactly why blanket claims about "peptides" as a class should make you cautious. For the specific compounds and their use cases, see our peptide therapy guide.

NAD+: Real Interest, Inconclusive Evidence

NAD+ therapies — IV infusions and oral precursor supplements — remain heavily marketed for energy and cellular anti-ageing, and interest hasn't slowed. But multiple 2026 clinical reviews describe the evidence for NAD+ supplementation as still inconclusive, particularly around optimal dosing, the most effective delivery method, and long-term outcomes in otherwise healthy adults. NAD+ levels genuinely do decline with age, and boosting them is biologically plausible — plausibility and proof are not the same thing, and it's worth being direct about which one currently applies here.

Why the Gap Exists

Both categories share a structural problem: the underlying biology is genuinely interesting, the clinical trials needed to confirm real-world benefit at scale are expensive and slow, and the consumer market has moved much faster than the research. That's not unique to longevity medicine, but it means the marketing language you'll encounter is often years ahead of the peer-reviewed evidence backing it.

What This Means for a Responsible Protocol

• Specificity over category-level claims. "Peptides work" isn't a useful statement. Which peptide, for which indication, with what evidence, matters.
• Honest framing from your provider. A clinic that tells you NAD+ is a "cutting-edge, proven cellular rejuvenation treatment" without qualification isn't giving you the full picture.
• Monitoring, not just administration. If you're using these therapies, biomarker tracking before and after gives you actual evidence of whether it's working for you specifically — rather than relying on how you feel, which is notoriously unreliable for this category.

The Bottom Line

Peptides and NAD+ are worth discussing with a qualified physician, and for the right individual and indication, can be a reasonable part of a broader protocol. They are not a substitute for the more boring, better-evidenced fundamentals — sleep, metabolic health, exercise, and the biomarker-driven personalisation covered in our precision longevity overview.