There are many growth hormone peptides, and they can be confusing. This guide sorts them by how they work. It explains the one distinction that matters most for safety, and lays out why we focus on the two with the strongest research and regulatory history: sermorelin and tesamorelin.
Reviewed by Dr. David Oliak, board-certified surgeon
Updated July 2026
Growth hormone supports body composition, recovery, sleep, and tissue repair.
From early adulthood, GH secretion falls steadily, a process sometimes called somatopause, and with it come changes many people notice in midlife: more fat, less muscle, slower recovery, poorer sleep.
The interest in GH peptides comes from a specific idea. Rather than injecting growth hormone directly, which overrides the body's own control, prompt the body to release more of its own GH in a natural pattern.
Every peptide on this page works through the same chain. The peptide signals the pituitary gland to release growth hormone; growth hormone travels to the liver, which produces IGF-1; and IGF-1 carries most of the effects people are seeking.>
Growth hormone also has some direct actions, particularly on fat, but IGF-1 is the principal mediator, and it is measurable in a simple blood test. That is why IGF-1 is the number we check before starting and follow during treatment.
The peptides differ in how they raise IGF-1; the goal is always the same: a meaningful but age-appropriate rise, not a supraphysiologic one.
GH-stimulating peptides act on one of two receptors, and this is the simplest way to organize the field.
GHRH-receptor analogs* mimic growth-hormone-releasing hormone, the body's own "release GH" signal. They augment your natural pulses of GH while leaving the body's regulation, including the negative feedback from IGF-1, intact. Sermorelin, tesamorelin, and CJC-1295 are in this group.
Ghrelin-receptor secretagogues* act on a second, different receptor (the one ghrelin uses) to prompt GH release through a separate channel. Ipamorelin, the GHRPs (GHRP-2, GHRP-6), and the oral compound MK-677 are in this group. They are sometimes combined with a GHRH analog to stimulate both pathways at once.
The distinction that matters most: pulsatile vs. sustained**> Beneath the receptor grouping is the single question that decides how physiologic a peptide is: does it preserve your natural, pulsatile rhythm of GH release, or does it flatten it into a continuous, above-normal elevation?
A healthy body releases GH in pulses, mostly at night, and those pulses are switched off by feedback when IGF-1 rises. GHRH analogs like sermorelin and tesamorelin work with that system: they increase the size of your natural pulses, but the pulses and the feedback remain.
Tesamorelin is stronger than sermorelin, not because it makes the elevation last longer, but because it stimulates each pulse more forcefully, producing a larger rise in IGF-1. The pattern stays natural; the amplitude increases.
CJC-1295 with DAC is the clearest counterexample. Its structure gives it a half-life of roughly a week, which produces a sustained "bleed" of GH and an IGF-1 level held continuously above baseline, without the normal peaks and troughs.
That is a fundamentally different, non-physiologic pattern, and its long-term implications are not well understood. This is the pattern we want to avoid, and it is a large part of why we favor the peptides that keep GH pulsatile.
Most GH peptides are not FDA-approved, and it is worth being precise about the two exceptions.
Tesamorelin is FDA-approved, marketed as Egrifta, but only for the reduction of excess abdominal fat in HIV-associated lipodystrophy. Its use for general wellness or body composition in people without that condition is off-label, and the compounded form we would prescribe is not the branded, approved product. Even so, it is the GH peptide with the strongest clinical trial evidence.
Sermorelin was FDA-approved, marketed as Geref, and used for growth hormone deficiency and pituitary testing. That product was discontinued years ago for commercial reasons, not safety, and sermorelin is now available through compounding. Its regulatory history and long clinical track record are why it remains a first-line option.
The remaining peptides, including CJC-1295, ipamorelin, the GHRPs, and MK-677, are not FDA-approved and are less studied. That does not make them useless, but it does place them outside our default approach.
We favor the two GHRH analogs with the best evidence and the most physiologic action: sermorelin and tesamorelin. Tesamorelin is our default when a larger IGF-1 response is the goal; sermorelin is a gentler, lower-cost option.
Both are dosed daily, toward bedtime, to align with the body's natural nighttime GH release. We use them as targeted tools within a plan built on the evaluation — chosen for a defined goal and matched to your labs, not selected from a menu.
Because every effect runs through IGF-1, we require a laboratory evaluation, including IGF-1, before starting. Because the aim is an age-appropriate rise rather than a supraphysiologic one, we follow IGF-1 during treatment to guide dosing. GH peptides are gated behind a full evaluation for this reason.
When a case calls for it, a ghrelin-pathway peptide such as ipamorelin may be added to a GHRH analog to stimulate both pathways, but that is a considered addition, not our starting point.
When we choose among GH peptides, the deciding question is whether a peptide keeps growth hormone pulsatile and under the body's own feedback, or forces it into a sustained, above-normal state. Sermorelin and tesamorelin do the former: they amplify your natural pulses, and IGF-1 can be titrated to an age-appropriate range and measured.
That combination of the strongest evidence and the most physiologic action is why they are our default, and why we treat the sustained-elevation peptides with caution.
— Dr. David Oliak, board-certified physician and surgeon
Both are GHRH analogs, and both produce their effects the same way, through a rise in IGF-1. The practical difference is strength. Tesamorelin stimulates each GH pulse more forcefully and produces a larger IGF-1 increase, which makes it the stronger choice. Sermorelin is gentler, produces a more modest rise, and costs less.
Both are dosed daily at night. The right choice depends on your goals and your baseline labs, which is what the evaluation is for. For the full comparison, including how each affects IGF-1 and how we choose, see the dedicated pages below.
Because every effect runs through IGF-1, we require a laboratory evaluation, including IGF-1, before starting. Because the aim is an age-appropriate rise rather than a supraphysiologic one, we follow IGF-1 during treatment to guide dosing. GH peptides are gated behind a full evaluation for this reason.
When a case calls for it, a ghrelin-pathway peptide such as ipamorelin may be added to a GHRH analog to stimulate both pathways, but that is a considered addition, not our starting point.
Reported side effects are generally mild and can include fluid retention, joint discomfort, and local injection-site reactions, which is one reason we titrate to an age-appropriate IGF-1 rather than pushing levels higher.
Because IGF-1 is a growth signal, GH peptides are not appropriate for people with active cancer, and are used cautiously where risk factors exist; your provider will review your history before prescribing. These peptides are not FDA-approved for wellness use and are prescribed off-label, under supervision, with informed consent.
The peptides we prescribe are compounded for human use by a licensed pharmacy, dispensed on a prescription, and supervised by a physician, with IGF-1 monitoring built in. Most peptides sold online are labeled "research use only," meaning not for human use, and are produced without a regulatory framework to confirm their contents.
With GH peptides, where dosing to a lab target is the entire point, that supervision is essential.
Begin with an evaluation.
Growth hormone peptides are prescribed only after a full evaluation, including IGF-1, and are titrated to your labs over time. Start with a comprehensive evaluation to see whether they fit your goals. To speak with us first, call 714-671-2005.
Tesamorelin — the stronger GHRH analog
Sermorelin — the gentler, lower-cost option
Tesamorelin vs. Sermorelin — the full comparison
Why "research use only" peptides are a problem
For most people, the choice is between sermorelin and tesamorelin, the two best-studied GHRH analogs. Tesamorelin is stronger and produces a larger IGF-1 rise; sermorelin is gentler and less expensive. The right one depends on your goals and your baseline IGF-1, which is why we evaluate labs before choosing.
Tesamorelin is FDA-approved, but only for HIV-associated lipodystrophy; its use for general wellness is off-label, and the compounded form is not the branded product. Sermorelin was previously FDA-approved (Geref) and later discontinued for commercial reasons; it is now compounded. The other GH peptides are not FDA-approved.
These are less studied and not FDA-approved. CJC-1295 with DAC in particular produces a sustained, non-pulsatile elevation of IGF-1 that we consider non-physiologic. Ipamorelin, a ghrelin-pathway peptide, is sometimes added to a GHRH analog in select cases, but is not our default.
Yes. Because every effect runs through IGF-1, we require an IGF-1 evaluation before starting and follow it during treatment to keep levels in an age-appropriate range. GH peptides are prescribed only after a full evaluation.
