Sermorelin, tesamorelin, CJC-1295 and ipamorelin compared

Four peptides aimed at the same axis by two different mechanisms. What separates them, what is FDA approved, and what gets monitored.

Key takeaways

  • None of these four are growth hormone. They act upstream and prompt your own pituitary to release GH in its natural pulsatile pattern.
  • Sermorelin, tesamorelin and CJC-1295 are GHRH analogs. Ipamorelin works through the ghrelin receptor, a separate pathway.
  • Tesamorelin is FDA approved for HIV-associated lipodystrophy. The others are prescribed as compounded preparations, which is not the same regulatory category.
  • IGF-1 is the marker used to confirm the axis is responding and to keep it inside an age-appropriate range.
  • Providers screen history in this class before prescribing, including malignancy history and glucose handling.

These are not growth hormone. They act upstream, prompting your pituitary to release its own GH in pulses, which is a different intervention from injecting GH directly.

Sermorelin, tesamorelin and CJC-1295 are GHRH analogs and differ mainly in how long they last. Ipamorelin works through the ghrelin receptor instead, which is why it is sometimes paired with a GHRH analog.

Tesamorelin is FDA approved for one specific indication. The others are prescribed as compounded preparations, which is a different regulatory category and worth understanding before you start.

Two mechanisms, one axis

Your pituitary releases growth hormone in pulses, mostly during deep sleep, under two opposing controls: growth hormone releasing hormone, which promotes release, and somatostatin, which restrains it. Ghrelin signaling, through the growth hormone secretagogue receptor, provides a third, separate push.

That is the entire map for this class of peptides. GHRH analogs imitate the promoting signal. Ghrelin receptor agonists use the other door. Either way, the hormone released is your own, in your own pulses, and the axis retains its feedback loop.

This is the substantive difference from injecting recombinant human growth hormone, which supplies a constant external supply and suppresses the natural pattern. Preserved pulsatility is a real pharmacological advantage of this class. Whether it translates into better clinical outcomes has not yet been settled by large trials.

The GHRH analogs

Three of the four are variations on the same idea, and they differ mainly in how long the signal lasts.

  • Sermorelin is GHRH 1-29, the shortest active fragment of natural GHRH. It has a very short half-life, on the order of minutes, which produces a brief pulse close to the body's own pattern. It is the longest-used of the group in this setting.
  • Tesamorelin is a stabilized GHRH analog, modified to resist enzymatic breakdown so it lasts longer than sermorelin. It is the only peptide in this group with FDA approval, granted for reduction of excess visceral abdominal fat in HIV-associated lipodystrophy, based on randomized trials in that population. Use for anything else is off-label.
  • CJC-1295 is a modified GHRH analog. The distinction that matters is whether the preparation includes a drug affinity complex, or DAC, which extends its duration substantially. Without DAC, it behaves closer to a short pulse. Preparations vary, and the version you are prescribed is a fair question to ask.

Ipamorelin, and why it is paired

Ipamorelin is a selective agonist at the growth hormone secretagogue receptor, the same receptor ghrelin acts on. It prompts GH release through a pathway independent of GHRH.

Selectivity is the reason it is used rather than earlier compounds in its class. It was characterized as stimulating GH release with comparatively little effect on cortisol and prolactin, in contrast with less selective secretagogues. That is a pharmacology finding from preclinical and early work, not an outcomes claim.

Because the two mechanisms are separate, ipamorelin is often combined with a GHRH analog such as CJC-1295, on the reasoning that pushing two levers produces a larger release than either alone. The mechanistic logic is sound. Randomized outcome data on the combination in healthy adults is thin, and that is worth saying plainly.

What the evidence supports, and what it does not

The clearest evidence in this group belongs to tesamorelin, in its approved indication, where randomized controlled trials showed reductions in visceral adipose tissue in patients with HIV-associated lipodystrophy.

Outside that, the evidence is thinner. There is good mechanistic evidence that these peptides raise GH and IGF-1, which is well established. What does not yet exist is a body of large randomized trials in healthy or aging adults measuring specific outcomes for body composition, sleep quality, recovery or longevity. It is also worth keeping the growth hormone literature and the secretagogue literature separate, because raising your own GH pulses and replacing GH from outside are not the same intervention.

So the honest framing: a well understood mechanism, established effects on the axis, and an outcome literature that is still developing. That is a reasonable basis for a monitored plan with labs, and a poor basis for a guarantee. If the evidence changes, this page changes.

Monitoring and screening

The reason IGF-1 gets measured before and during therapy is that it is the readout of the axis you are acting on, and the objective is an age-appropriate value rather than a maximal one. Higher IGF-1 is not a better result.

Providers also consider glucose handling, since GH can reduce insulin sensitivity, which makes fasting glucose, fasting insulin and HbA1c relevant to follow. History of malignancy is screened because GH and IGF-1 are growth signals, and that is a prescriber's judgment rather than an intake checkbox. Fluid retention, joint discomfort and carpal tunnel symptoms are the reported effects most associated with GH excess and are the ones to report if they appear.

All of this is why this class belongs with a provider and a lab panel rather than in a shopping cart.

How Baseline handles this class

Baseline is a wellness consulting practice and does not prescribe. Intake, and any lab work you choose to have done, are reviewed by an independent licensed provider network, that network makes the prescribing decision, and the specific peptide, dose and schedule come from them.

All four are documented here for education. Ordering status is shown on each therapy page, and the practical route is the same either way: speak with a consultant, and the provider decides what fits. For anyone considering this class we recommend IGF-1 before and during, and the prescribing physician sets the monitoring plan.

What this means for you

Understand which mechanism you are being offered and whether it is FDA approved or compounded, then make sure IGF-1 is measured before you start and re-checked during. A GH peptide without lab monitoring is a product, not a protocol.

Therapies discussed here

References

  1. FDA prescribing information, tesamorelin (Egrifta), approved indication
  2. Falutz et al., randomized trials of tesamorelin in HIV-associated abdominal fat accumulation, New England Journal of Medicine and Journal of Clinical Endocrinology and Metabolism
  3. Raun et al., ipamorelin, the first selective growth hormone secretagogue, European Journal of Endocrinology, 1998
  4. Teichman et al., prolonged stimulation of growth hormone and IGF-1 secretion by CJC-1295, Journal of Clinical Endocrinology and Metabolism, 2006
  5. Biomarker hub: IGF-1
  6. Before you start: What compounded actually means

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