Sermorelin and tesamorelin are the two growth hormone peptides we favor, and they work the same way: both prompt your own pituitary to release GH, which raises IGF-1. The practical question is strength. This page compares how each affects IGF-1, where the evidence stands, how they are dosed, what they cost, and how we choose.
Reviewed by Dr. David Oliak, board-certified surgeon
Updated August 2026
Sermorelin and tesamorelin are both analogs of growth-hormone-releasing hormone (GHRH), the body's own signal for GH release. Sermorelin is the shortest fully active fragment of that hormone, FDA-approved in the 1990s (as Geref) and later discontinued for commercial reasons. Tesamorelin is a stabilized, longer-lasting version, FDA-approved in 2010 (as Egrifta) for HIV-associated lipodystrophy.
Each signals the pituitary to release your own growth hormone in its natural, pulsatile pattern, which the liver converts into IGF-1, the marker we measure and the main driver of the effects.
People consider either one because GH and IGF-1 fall with age; the aim is to restore them toward an age-appropriate level. Because the two share a mechanism, the choice between them is not about *what* they do but *how strongly* they do it.
The key difference is half-life. Sermorelin clears very quickly, in roughly ten to twenty minutes, so it delivers a brief, gentle stimulus to the pituitary. Tesamorelin is structurally stabilized and lasts longer, roughly half an hour, so it engages the pituitary more forcefully.
The result is that tesamorelin drives a substantially larger rise in IGF-1. In effect, tesamorelin is a more potent, degradation-resistant version of sermorelin.
It is worth being precise, because it is often described incorrectly: tesamorelin does not create a *sustained,* continuous elevation of growth hormone. Like sermorelin, it amplifies your natural GH pulses and leaves the body's feedback intact; it simply stimulates each pulse harder. Both keep the physiologic, pulsatile pattern. Tesamorelin is stronger, not less natural.
Both are among the best-evidenced peptides we offer; they differ in the strength of the effect, not in whether the mechanism is real.
Both have genuine regulatory histories, which sets them apart from most peptides.
Tesamorelin has the stronger formal evidence and is the growth hormone peptide we use most. In our practice, patients on it most often report better sleep and improvements in body composition. They also report maintenance — sometimes growth — of muscle, including while on GLP-1 weight-loss medication.
Our own use of sermorelin is more limited, reserved for when a gentler rise or lower cost is the priority.
Both are prescribed through a monthly membership (medication, shipping, and follow-up visits included; labs billed separately at Quest). A comprehensive evaluation is required first. For current pricing, see the peptide pricing page.
Many clinics run GH peptides in cycles, with a few weeks off every couple of months. We dose them daily and continuously instead, and there is a reason.
GHRH analogs preserve the body's own feedback: the pituitary stays under normal control and GH release remains self-limiting, so the empirical "washout" that makes sense for direct growth hormone has no pharmacologic basis here.
Tesamorelin's own approved product, Egrifta, is dosed once daily and continuously, and in its trials visceral fat returned when treatment was paused. Rather than guess with a calendar, we track IGF-1 and adjust the dose to it. The lab, not a cycle schedule, tells us whether the dose is right.
Tesamorelin has the strongest clinical evidence of any GH peptide, but the context matters: its body-composition and visceral-fat data come from trials in HIV-associated lipodystrophy, the condition for which it is FDA-approved (as Egrifta). Its use for general wellness or body composition outside that population is off-label.
Sermorelin was FDA-approved (as Geref) for growth hormone deficiency and pituitary testing, and was later discontinued for commercial reasons; it is now compounded. Neither is FDA-approved for wellness or anti-aging use.
Our verdict: the way we choose is straightforward. Tesamorelin is our default when the goal calls for a larger IGF-1 response, and it has the strongest evidence behind it.
In our practice it is the one we use most. Patients most often notice better sleep, body composition, and muscle maintenance, even alongside GLP-1 weight-loss treatment.
Sermorelin is the right choice when a gentler rise is appropriate or cost is a consideration, though our own use of it is more limited.
Because both work through IGF-1, we do not guess: we measure IGF-1 at baseline, choose the peptide and dose to reach an age-appropriate target, and re-check it.
Either one is used as a targeted tool within a plan built on the evaluation — the number on the lab, not the name of the peptide, drives it.
— Dr. David Oliak, board-certified physician and surgeon
Both peptides are dosed daily at bedtime, on an empty stomach, to align with the body's natural nighttime GH release. We start conservatively and titrate toward an age-appropriate IGF-1 rather than the highest tolerable level, confirming the response on repeat labs at roughly eight to twelve weeks and then quarterly.
Because growth-hormone secretagogues can affect blood sugar, we also recheck glucose and A1c. Both are gated behind a comprehensive evaluation, including baseline IGF-1, which is what makes titration possible.
With any injected peptide, the source is a safety issue, not a detail. We prescribe compounded, human-use product through a licensed pharmacy, not research-only material sold online, which is labeled not for human use and produced without a regulatory framework to confirm its contents.
Reported side effects for both are generally mild and can include fluid retention, joint discomfort, and injection-site reactions, which is one reason we titrate to a physiologic IGF-1 rather than pushing it higher.
Because IGF-1 is a growth signal, GH peptides are not appropriate for people with active or recent cancer, and are used cautiously in uncontrolled diabetes and proliferative diabetic retinopathy.
Both are prescribed off-label, under supervision, with informed consent. Why "research use only" peptides are a problem →
Let's begin
Sermorelin and tesamorelin are prescribed only after a comprehensive evaluation, including IGF-1, and are dosed to your labs over time. The evaluation is what matches the right one to you as a targeted part of a plan — start there to determine which fits your goals. To speak with us first, call 714-671-2005.
Growth hormone peptides, explained
Tesamorelin — the stronger GHRH analog
Sermorelin — the gentler, lower-cost option
Why "research use only" peptides are a problem
Tesamorelin. Its longer half-life stimulates the pituitary more forcefully and produces a substantially larger rise in IGF-1. Sermorelin is gentler and produces a more modest rise.
Essentially, yes: both are GHRH analogs on the same receptor, and tesamorelin is a more potent, degradation-resistant version. Both keep GH release pulsatile and feedback-regulated; tesamorelin simply drives each pulse harder, which is why IGF-1 rises more. It does not produce a continuous, non-pulsatile elevation.
No. GHRH analogs preserve the body's own feedback, so a washout has no pharmacologic basis, and pausing can let gains reverse. We dose daily and continuously and track IGF-1 to guide the dose instead.
Both are prescribed through a monthly membership that includes medication, shipping, and follow-up visits; labs are billed separately at Quest. Sermorelin is one vial per month; tesamorelin is one, two, or three vials by dose tier. Current pricing is on our peptide pricing page. A comprehensive evaluation is required first.
Tesamorelin is FDA-approved, but only for HIV-associated lipodystrophy; use for general wellness is off-label. Sermorelin was previously approved and is now compounded. Neither is approved for anti-aging or wellness use.
