CJC-1295 and growth hormone: a measured look at the evidence

The bodybuilding forums talk about CJC-1295 like it’s settled science. Long-acting GHRH analog. Lifts your GH for days, your IGF-1 for weeks, recomp gets easier, sleep gets deeper, you train harder. Twenty years of safety data, somebody helpfully posts.

The actual research base for CJC-1295 is one PK trial in 2006, a follow-up the same year, and a long quiet since.

That’s not a takedown. The 2006 trial was real, well-designed, and produced exactly the GH and IGF-1 curves the chemistry promised. The compound does what its label says it does at the level of hormone biology. The gap is everywhere else.

Why CJC-1295 keeps showing up

Most growth hormone secretagogues have one obvious flaw. They wear off too quickly.

Native GHRH lasts minutes. Sermorelin — the 29-amino-acid fragment that actually cleared the FDA decades ago — lasts not much longer. To get a meaningful GH bump you have to inject often, time it carefully, and accept that the body’s own pulsing rhythm is going to push back. The peptide chemistry community has spent decades trying to engineer around that.

CJC-1295 is what that engineering looks like when it works. It’s a modified version of human GHRH(1-29) with four amino acid substitutions to resist enzymatic breakdown, plus a chemical handle at the C-terminus that latches onto a cysteine on serum albumin. Albumin is the most abundant carrier protein in your blood and has a half-life of about three weeks. By riding piggyback on albumin, CJC-1295 turns minutes of activity into days.

A 2005 paper in Endocrinology by Jetté and colleagues at ConjuChem is the founding document. The group built three candidate maleimido derivatives, tested each as an albumin conjugate, and identified CJC-1295 as the best of the three — a 4-fold increase in GH AUC over hGRF(1-29) in rats, with the bound peptide remaining in plasma past 72 hours. That’s the moment CJC-1295 stopped being a chemistry candidate and started being a named compound.

The naming matters because there are two compounds being sold under similar names, and they do extremely different things. More on that in a minute.

The mouse-to-human gap is shorter here than usual

For most peptides on the longevity menu, the human file is empty. CJC-1295 is the rare one where there’s an actual human trial.

A 2006 study in the Journal of Clinical Endocrinology and Metabolism by Teichman and colleagues took the DAC variant into healthy adults aged 21 to 61. Two randomised, placebo-controlled, double-blind ascending-dose sub-studies. The findings were exactly what the chemistry predicted. Single subcutaneous doses raised mean plasma GH 2-to-10-fold above baseline for at least 6 days. Mean plasma IGF-1 went up 1.5-to-3-fold for 9 to 11 days. After multiple weekly doses, IGF-1 stayed above baseline for up to 28 days. Estimated half-life of the bound compound was 5.8 to 8.1 days. No serious adverse events. Injection-site reactions were the most common finding.

That is a clean Phase 1 PK/PD result. It confirmed that the albumin-binding strategy worked in people, that the GH/IGF-1 curves were sustained the way the chemistry suggested, and that the safety profile at the tested doses was unremarkable.

A second 2006 follow-up by Ionescu and Frohman in the same journal added an important detail. The natural worry with sustained GHRH stimulation is that you’d flatten the body’s own GH pulses — turn the staccato into a hum. The follow-up looked specifically and found the pulse pattern was preserved. The peptide kept stimulating the receptor without erasing the rhythm the receptor normally fires on. Mechanistically, that’s the design working as intended.

This is more developed human data than almost any peptide on the longevity menu can claim. Twenty years of safety it is not. Two well-run Phase 1 papers from the same year it is.

The without-DAC compound is not the same compound

This is where the marketing and the chemistry actively disagree, and the disagreement matters.

The compound in the Teichman and Ionescu papers — the one the literature characterised — is CJC-1295 with DAC. DAC stands for Drug Affinity Complex, which is the technical name for the maleimido handle that lets the peptide bind albumin. The DAC is what makes the half-life 5 to 8 days.

The compound widely sold to consumers as CJC-1295 is often CJC-1295 without DAC — sometimes called MOD-GRF(1-29) by the more careful suppliers. Same four amino acid substitutions for stability. No albumin-binding handle. The half-life is roughly half an hour.

These compounds share a name. They do not share a pharmacology. The DAC variant gives you weeks of elevated GH/IGF-1 on a single dose. The no-DAC variant gives you a 30-minute pulse, dosed multiple times a day, with effects on GH/IGF-1 measured in hours not days.

When a forum thread or a clinic explains CJC-1295 and references the Teichman 2006 data, ask which compound was studied and which compound is being sold. If the answer is they’re the same thing, the answer is wrong.

What we don’t actually know

Everything between hormones go up and you live better is uncharted in CJC-1295.

The Teichman 2006 trial measured GH and IGF-1. It did not measure body composition. It did not measure functional fitness. It did not measure sleep quality. It did not measure cognition. It did not measure any of the things that get used in the marketing copy.

The body-composition pitch — that elevated GH and IGF-1 over weeks must translate into more lean mass or less fat — is extrapolation from the hormone biology, not measurement of what happened. Nobody has run that trial in CJC-1295. The closest evidence in the recent literature is the 2026 Am J Sports Med primer by Mayfield and colleagues, which reports that a CJC-1295 plus ipamorelin combination improved tetanic tension in a glucocorticoid-induced muscle loss mouse model. The same review then notes, explicitly, that no human orthopaedic data exists for the combination.

That’s the actual state of evidence in 2026. A confirmed Phase 1 PK/PD signal from 2006. A mouse-muscle finding in a stack combination from 2026. The 2026 Frontiers in Aging review by Mavrych and colleagues reaches the same conclusion about the whole growth-hormone-modulation peptide cluster — mechanism story is plausible, optimal dosing is not agreed, validated biomarkers for efficacy are not established.

The bridge from Phase 1 PK/PD in 50 people in 2006 to I should be on this for years to recomp is the bridge nobody has built. Not in CJC-1295 specifically, and not in a closely related compound either.

The longer-term question nobody has addressed

This is the part the safety claims tend to glide past.

The Teichman trial dosed people for 28 to 49 days. The Ionescu follow-up looked at pulsatility under continuous stimulation for a comparable window. After that, the controlled human evidence stops.

People prescribed CJC-1295-with-DAC for anti-aging often stay on it for months or years. There’s no published controlled trial that ran that long. The natural worry is the IGF-1 question. IGF-1 is a growth signal, and chronically elevated IGF-1 in adults has plausibly different long-term implications than transient elevation under a single Phase 1 protocol. Multiple cohort studies of natural IGF-1 levels and downstream outcomes have produced mixed and sometimes opposite findings. None of those studies were CJC-1295 users, because there’s never been a long-term cohort study of CJC-1295 users to do.

A reasonable doctor running CJC-1295 for a patient is doing it on the strength of a clean 2006 Phase 1 plus mechanism plus pharmacology, with the long-term picture filled in by what’s known about GH-axis biology in general. That’s not nothing. It’s also not the same as evidence that two years of CJC-1295 are safe and useful.

Where the FDA actually sat — December 4, 2024

CJC-1295 has never received FDA marketing authorisation for any indication. There’s no NDA. No BLA. No approved label.

It is not on the PCAC July 23–24, 2026 agenda — but the reason is sharper than the marketing usually allows. The FDA already reviewed CJC-1295 in 2024. After CJC-1295 was removed from the Category 2 list in September 2024 and referred to PCAC, the committee evaluated it at the December 4, 2024 meeting and voted against inclusion on the 503A bulk drug substances list. The agency’s stated reasoning was the standard pattern: insufficient human safety data, mechanistic concerns about unintended endocrine effects from sustained GH-axis stimulation, and lack of reproducible efficacy data outside small or open-label trials. So the docketed-substances framing is incomplete on its own. CJC-1295 isn’t on the July 2026 docket because the agency already asked the question, and the answer it got was no.

WADA is the cleaner line. Growth-hormone-releasing factors are on the 2026 S2 prohibited list — peptide hormones, growth factors, related substances, and mimetics — and CJC-1295 falls inside that category. Athletes subject to WADA testing should treat it as banned in and out of competition. The marketing’s not specifically named framing doesn’t override the category language.

What would settle the CJC-1295 case

The honest scientific endpoint isn’t can CJC-1295 raise IGF-1 in healthy adults. We’ve known the answer since 2006. The harder questions all involve trials nobody has run.

A controlled trial in healthy adults running longer than the 2006 PK windows, with body-composition and functional endpoints, instead of inferring from hormone curves.

Independent replication of the Teichman and Ionescu work in modern protocols, ideally with the variant being sold to consumers (the no-DAC form), not just the DAC variant that was characterised twenty years ago.

A safety dataset that goes past weeks. The Phase 1 reports showed no serious adverse events in the dosing windows tested. What happens at month 12 or year 3 is a question the existing record can’t answer.

And a serious look at whether the CJC-1295 plus ipamorelin stack — the most common clinical combination — does anything in humans beyond what the 2006 single-agent data already showed. The mouse muscle finding in Mayfield 2026 is suggestive. A controlled human trial of the combination, with strength or recovery endpoints, would tell you whether the suggestion holds up.

Some of those trials might happen. Most of them won’t, because there’s no commercial entity with an active development program to fund them. CJC-1295’s original sponsor, ConjuChem, ceased operations more than a decade ago. The molecule lives on in compounding because the chemistry is straightforward and the demand is real, not because anyone is currently running it through the FDA-approval pathway.

Which leaves the buyer where they started. Real Phase 1 data. Coherent mechanism. Two distinct compounds sold under one name. No human evidence for the lifestyle outcomes the marketing keeps describing. No long-term safety dataset.

That’s CJC-1295 in 2026. More than nothing. Less than the forums would have you believe.

Where CJC-1295 lands

The hardest part of buying CJC-1295 from a grey-market source isn’t the trust-the-vendor problem. It’s that CJC-1295 names two compounds with wildly different pharmacology and you have no way to verify which one you got. Half-hour half-life or eight-day half-life, dosed three times a day or once a week, riding on extrapolation from a Phase 1 paper that’s old enough to drink. The version you actually want depends on which problem you’re trying to solve. The vial you actually receive depends on whoever filled it.

Wolverine Health is being built so that the answer to which variant is this is on the label, the prescribing physician knows the difference, and the compounding pharmacy is one a state board can name. Real prescriptions, US-licensed pharmacies, every batch third-party tested. We’re not selling you ahead of the science — including the science that says CJC-1295’s human evidence base is one good Phase 1 in 2006 and a quiet twenty years since. Join the waitlist if you want a heads-up the moment that version is available.