Sermorelin and NAD+: what has actually been measured in cellular longevity

Two very different molecules, one shared problem of language. NAD+ is a coenzyme involved in the energy metabolism of every cell; sermorelin is a peptide that stimulates the pituitary. Neither one “restores biological youth”, and that phrase — which this article used to carry in its title — describes no measured result. What has been measured is something else, and it follows.

If you are looking for the clinical programme, it is set out in peptide therapy. Here is the evidence, with its limits.

Sermorelin: what it is and what it does

Sermorelin is the synthetic form of the first 29 amino acids of GHRH, the hormone that releases the pituitary. Its mechanism is described: it binds specific receptors in the pituitary and increases the production and secretion of the gland's own endogenous growth hormone. It is not growth hormone injected from outside: it is a signal asking the pituitary to release its own.

That difference is what sustains the clinical interest. The source arguing for its use in longevity — a commentary in *Clinical Interventions in Aging* (2006, DOI `10.2147/ciia.2006.1.4.307`) — argues that stimulating the pituitary has advantages over giving recombinant growth hormone, because the body keeps its own regulation instead of receiving a fixed dose that the practitioner can only adjust by guesswork, guided by serum IGF-1.

And here is the limit, which deserves saying out loud: that source is a two-page commentary, not a controlled trial. It puts forward a reasonable physiological hypothesis; it does not measure clinical outcomes in healthy adults. I have not found controlled trials measuring whether that mechanism translates into anything a person can notice.

What the FDA's public databases say about sermorelin

I checked both public databases on 2026-10-05:

Database	Query	Result
DailyMed (NLM)	`drug_name=sermorelin`	0 presentations with current labelling
openFDA (Drugs@FDA and label)	`generic_name:"sermorelin"`	no results

In other words: no sermorelin presentation with current labelling appears in the FDA's databases today. In the United States such a peptide is dispensed as a compounded formulation from a 503A pharmacy, under an individualised prescription after a consultation — and a compounded medication is not FDA-approved: the agency does not review its safety, effectiveness or quality before it reaches a patient. For the legal detail, see the science behind compounded GLP-1 medications.

NAD+: the metabolism is well described; the clinical benefit is not

NAD+ is a central coenzyme in cellular energy metabolism, redox balance and several signalling pathways related to ageing. That is reasonably well described and reviewed, among others, in a reference review in *Nature Reviews Molecular Cell Biology* (2021, DOI `10.1038/s41580-020-00313-x`).

The problem appears at the next step: the fact that the coenzyme matters inside the cell does not imply that supplementing it produces a clinical benefit. The most recent review I have read on supplementation — *Molecular Biology Reports*, 2026, DOI `10.1007/s11033-026-12351-3` — summarises the state of the question like this:

“Current evidence shows that oral NAD+ precursors such as nicotinamide riboside and nicotinamide mononucleotide can increase circulating NAD+ levels, although their clinical benefits remain variable and context-dependent. Intravenous NAD+ administration is less well characterized and lacks robust clinical validation.”

It adds a nuance usually missing from the marketing: the response is not linear. Dose, age, metabolic state and route of administration all matter, and the system has feedback and saturation mechanisms. The review's conclusion is not “it works”, it is that well-designed clinical studies are needed to define effective and safe strategies.

Why the phrase “restores biological youth” had to go

This is not a matter of commercial prudence. The phrase has no measurable subject:

“Biological youth” is not a validated clinical endpoint. There is no agreed criterion that can be measured in a person and called “rejuvenation”. What gets measured are biomarkers and specific parameters, not youth.
A biomarker that rises is not an outcome. Circulating NAD+ rising is a data point; whether that changes anything in a person's health is a different question, and per the review cited it still has no firm answer.
“Restore” implies giving something back its previous state, and that is a promise of a result. Neither the trials nor the reviews support it.

What the evidence does support is smaller and more useful: a described mechanism, a measurable biomarker, and a set of open questions. That is an honest article. The other thing was a promise.

What this article does not say

No doses and no administration schedules, for either sermorelin or NAD+.
No promises of longevity, biological age or years of life.
The term “anti-aging” is not used, because it describes a commercial aspiration, not a measurable clinical goal.
Nothing is sold here: what patients engage is the clinical evaluation and follow-up; the medication is dispensed by a 503A pharmacy under prescription.

They are given by different routes and at very different frequencies; the detail is in why some peptides are administered once a week and in what a peptide can do.

Frequently asked questions

Does taking NAD+ precursors raise the body's NAD+?

Yes, at circulating level. The 2026 review describes this for oral NAD+ precursors. What is not established is that this increase by itself produces a clinical benefit.

Does intravenous NAD+ work?

It is the route with the least support: the same review notes that intravenous NAD+ administration is less well characterised and lacks robust clinical validation. Nor does it appear as an FDA-approved product.

Is sermorelin FDA-approved?

No sermorelin presentation with current labelling appears in DailyMed or the FDA's databases (verified 2026-10-05). It is dispensed as a 503A compounded formulation under prescription, and a compounded medication is not FDA-approved.

Can I measure my biological age?

You can measure specific biomarkers, and some have clinical value. What does not exist is a single validated number summarising “your biological age” that could be used to evaluate a treatment. If a product offers you that number as proof, it is selling you a marker, not an outcome.

In which states is it available?

In 49 states — all but California — plus Washington D.C. and Puerto Rico. Details are on the territorial coverage page.

Sources

NAD+ biology and supplementation: From mechanisms to clinical perspectives. Mol. Biol. Rep. 2026. DOI `10.1007/s11033-026-12351-3`. PMID 42489969. Source of the quotes on oral precursors, the intravenous route, non-linear response and the need for clinical studies.
NAD+ metabolism and its roles in cellular processes during ageing. Nat. Rev. Mol. Cell Biol. 2021. DOI `10.1038/s41580-020-00313-x`. Role of NAD+ in energy metabolism and cellular ageing.
Walker, R. F. — Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin. Interv. Aging 2006;1(4):307–308. DOI `10.2147/ciia.2006.1.4.307`. PMID 18046908. Full text consulted (PMC2699646). Nature: commentary, not a clinical trial.
DailyMed (NLM) and openFDA. Query `sermorelin` returned no results on 2026-10-05: `https://dailymed.nlm.nih.gov/dailymed/services/v2/drugnames.json?drug_name=sermorelin`.
FDA — Human Drug Compounding Laws. `https://www.fda.gov/drugs/human-drug-compounding/compounding-laws-and-policies`. 503A regime, CGMP exemption and non-approval of compounded drugs.

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