Last Updated October 23, 2023

 October 23, 2023

Curious about how sermorelin vs. tesamorelin fare against each other for potential benefits like weight loss and muscle-building?

Inside this comprehensive comparison, we'll break down key differences between these two powerful research peptides, including in potential applications like:

  • Weight loss
  • Muscle-building
  • Skin care and enhancement

Keep reading to discover the latest clinical data on their structures, mechanisms, potential side effects, and dosing. In the end, we will also recommend our favorite vendor of research-grade peptides, including sermorelin and tesamorelin.

Buy research peptides from our top-rated vendor...

Disclaimer: contains information about products that are intended for laboratory and research use only, unless otherwise explicitly stated. This information, including any referenced scientific or clinical research, is made available for educational purposes only. Likewise, any published information relative to the dosing and administration of reference materials is made available strictly for reference and shall not be construed to encourage the self-administration or any human use of said reference materials. makes every effort to ensure that any information it shares complies with national and international standards for clinical trial information and is committed to the timely disclosure of the design and results of all interventional clinical studies for innovative treatments publicly available or that may be made available. However, research is not considered conclusive. makes no claims that any products referenced can cure, treat or prevent any conditions, including any conditions referenced on its website or in print materials.

What is Sermorelin?

Sermorelin, also known as growth hormone-releasing factor 1-29 (GRF 1-29), is a synthetic peptide that consists of the first 29 amino acids of endogenous growth hormone-releasing hormone (GHRH) [1].

Physiological GHRH secretion is what primarily regulates the synthesis of growth hormone (GH) in healthy individuals [2].

Sermorelin was first developed by pharmaceutical company EMD Serono as the shortest fragment of GHRH’s 44 amino acid sequence that is still fully functional and stimulates GH release [3]. Its shorter structure aside, sermorelin has been shown to have a similar half-life to GHRH [4].

EMD Serono marketed sermorelin under the trade name GEREF, which received approval by the United States Food and Drug Administration (FDA) in the form of subcutaneous injections for a variety of indications. Yet, GEREF was taken off the market in 2008 for commercial reasons at EDM Serono’s request.

Here is a timeline of sermorelin’s regulatory status over the years [5]:

  • 1990: Intravenous sermorelin was FDA approved as a GH stimulation test for the diagnosis of growth hormone deficiency (GHD). Later, arginine was added alongside the peptide to improve the test’s specificity.
  • 1997: Subcutaneous sermorelin was approved for therapy in short stature and idiopathic GHD in children.
  • 2008: EMD Serono discontinued commercial production of GEREF for reasons unrelated to its safety or effectiveness.

Sermorelin is available to qualified researchers as a reference material for educational and experimental purposes.

Sermorelin vs. Tesamorelin

What is Tesamorelin?

Tesamorelin (TH9507) is a synthesized version of GHRH, retaining its same 44 amino acid composition but enhanced via a trans-3-hexenoic acid attachment at the N-terminus.

This modification leads to an increased affinity with tesamorelin’s target receptors, and also offers greater resistance against degradation [6].

With a half-life of approximately 30-40 minutes, tesamorelin interacts with the GHRH receptors in the pituitary gland, prompting somatotroph cells to release an increased amount of growth hormone. Peak GH secretion usually occurs 30-60 minutes post injection [7, 8].

Tesamorelin was developed by Canadian firm Theratechnologies as a treatment for lipodystrophy associated with HIV/AIDS.

Lipodystrophy is a condition related to an abnormal distribution of body fat. It manifests with a noticeable loss of fat in areas like the arms, legs, or face, and accumulation in other areas like the abdomen and around internal organs.

In the case of HIV/AIDS, lipodystrophy is believed to be caused by certain antiretroviral treatments. The most concerning aspect of this condition is increased fat around (and inside) the internal organs—called visceral obesity. This may lead to metabolic complications, such as insulin resistance and type 2 diabetes.

Thus, lipodystrophy affects not only the patients' appearance but may impact their overall health.

Upon completion of rigorous phase-3 trials, the FDA granted approval for tesamorelin therapy in 2010 in HIV-associated lipodystrophy. The peptide is available to patients as a daily subcutaneous injection under the brand names Egrifta and Egrifta SV (SV denoting small volume) [9, 10]. Like sermorelin, tesamorelin is also available to qualified scientists for laboratory experimentation.

Sermorelin vs. Tesamorelin | Comprehensive Comparison

Sermorelin and tesamorelin both are GHRH receptor agonists that work to stimulate the physiological production of GH. Produced by the pituitary in pulses, GH can reach about 10ng/ml in men and 14ng/ml in women, according to reference ranges [11].

Notably, GH can be undetectable between pulses, even in healthy individuals. Thus, a single GH measurement is insufficient for providing information on a test subject’s total GH levels.

Instead, scientists have to perform multiple GH tests over time to see how peptides like sermorelin or tesamorelin may affect the hormone’s synthesis.

Then, the results can be plotted on a graph, forming a curve line that shows how GH levels rise and fall (Y axis) over time (X axis). The area under this graphed line, also known as the “area under the curve” (AUC), gives a complete picture of how much total GH is released during a given period.

According to clinical data, sermorelin and tesamorelin both work by influencing total pulse area and AUC. On the other hand, they do not appear to increase pulse frequency or cause supraphysiological GH levels [7, 12].

In addition, GH stimulates the production of an anabolic hormone called insulin-like growth factor-1 (IGF-1). Yet, IGF-1 does not follow the same pulsatile pattern and its levels depend on mean GH levels. This is why IGF-1 may also be used to boost growth hormone production.

IGF-1 is further thought to mediate the majority of GH's anabolic effects, such as the potential for lean body mass increase.

Here is the latest research on the effects of sermorelin and tesamorelin on GH and IGF-1 levels:

  • Sermorelin, in a study involving 11 senior male participants receiving 2mg/daily injections over a span of 6 weeks, amplified overall GH levels (measured by AUC) by 82%. This surge in GH concentrations persisted for roughly two hours post-injection. Levels of IGF-1 remained unchanged with this once-daily regimen [12].
  • Sermorelin at doses of 1mg and 2mg significantly increased both GH and IGF-1 in young and elderly male volunteers. Study authors reported that IGF-1 in the older men increased by 25% with the highest dose, reaching levels observed in the untreated younger individuals. Moreover, the increase in IGF-1 in elderly males persisted for two weeks after discontinuing sermorelin [13].
  • Tesamorelin, administered in doses of 2mg/daily for two weeks, resulted in 69% higher total GH (AUC) in 13 middle-aged healthy males. IGF-1 levels increased by a substantial 122% [7].
  • Tesamorelin was also administered to patients with type 2 diabetes at doses of up to 2mg/daily. Study authors reported a more modest 60% increase in IGF-1 after 12 weeks of therapy at this dosage [14].

In brief, both tesamorelin and sermorelin effectively increase GH and IGF-1, albeit at different rates. We will now individually look at the purported benefits of both compounds.

Sermorelin Benefits

The potential benefits of sermorelin stem from its ability to increase GH, which is a hormone that has been shown to help subjects burn fat, increase lean body mass, and stimulate cell proliferation.

Here are the most notable benefits of sermorelin as illustrated in clinical studies:

  • Muscle building and lean mass increase. Research conducted on older adults showed that administering sermorelin at a dose of 10mcg/kg daily for 16 weeks resulted in a significant increase in lean body weight, totaling 2.78lb. This effect occurred in male but not in female elderly subjects [15].
  • Skin appearance and cell proliferation. The aforementioned trial also noted a significant increase in skin thickness in both males and females. This increase is likely related to GH's effect on skin cell proliferation and collagen synthesis [15].

Tesamorelin Benefits

Similar to sermorelin, tesamorelin works by stimulating the release of GH, which has well-known anabolic effects on muscle tissue while stimulating fat loss.

Research on tesamorelin tends to report more significant weight loss and fat-burning results compared to sermorelin. Here are some of the most notable findings:

  • Weight reduction and fat loss. In a study in 60 abdominally obese subjects with diminished GH, tesamorelin led to a reduction of 3.7lb in body fat from after 52 weeks of 2mg/daily administration. The study participants also experienced an 8% decrease in visceral fat [16].
  • Lipodystrophy management. Tesamorelin is highly effective in reducing visceral fat in HIV/AIDS patients, with trials reporting up to -25% reduction in this parameter from baseline within 52 weeks [17].
  • Muscle building and lean mass increase. In a study in adults with HIV/AIDS, tesamorelin at a dose of 2mg/daily significantly reduced muscle wasting. After 26 weeks of therapy, the researchers observed a significant increase in muscle density and size at various body sites [18].

Currently, there are no clinical studies reporting an increase in skin thickness or improved skin appearance following tesamorelin therapy.

Sermorelin Side Effects

Sermorelin is well-tolerated based on available clinical studies. Its safety profile has specifically been demonstrated in pediatric populations, where it has been FDA-approved and used without significant adverse outcomes [12, 13].

However, like any therapeutic agent, there are potential side effects related to sermorelin use. Commonly reported side effects of sermorelin include injection site reactions, which may include:

  • Pain
  • Swelling
  • Bleeding
  • Inflammation
  • Induration

Further, one 16-week trial reported transient hyperlipidemia in a patient receiving sermorelin [15].

Researchers should also consider that compounds that increase GH, such as sermorelin, are contraindicated in subjects with a history of oncological conditions. This is because increased GH may stimulate cell proliferation and cancer progression.

Tesamorelin Side Effects

Tesamorelin has been FDA-approved for use in HIV-related lipodystrophy based on the favorable safety results of phase-3 trials that involved a total of over 800 participants [19].

Pooled trial data indicates the following side effects and their incidences [20]:

  • Injection site reactions – 24.5%
  • Joint pain – 13.3%
  • Peripheral edema and limb pain – 6.1%
  • Muscle pain – 5.5%
  • Tingling sensations – 4.8%
  • Worsened glycemic control (elevated glycated hemoglobin) – 4.5%
  • Hypersensitivity (allergic reactions such as skin rash) – 3.6%
  • Carpal tunnel syndrome – 1.5%

Injection site reactions were the most common adverse reaction and mainly included pain, redness, and itchiness.

Similar to sermorelin, tesamorelin is contraindicated in subjects with active malignancies.

Sermorelin vs. Tesamorelin | Dosage Calculator and Comparison

The available research indicates that both tesamorelin, and sermorelin should be administered daily via subcutaneous injections.

Trials report administering the peptides late in the evening, usually at bedtime. This helps to minimize the counter-regulatory action of GH against higher daytime insulin levels (and its potential for increasing insulin resistance).

The correct dosage of sermorelin or tesamorelin depends on the specific research goal. Below, we share some of the most commonly employed dosing protocols for each compound while referring to the latest clinical data.

Reference Sermorelin Dosing Protocol

Current data indicate that clinical sermorelin dosages have ranged from 1-2mg/daily, delivered in one or two daily injections for up to 16 weeks [21].

For research purposes, experts advise starting with a conservative dose of 0.5mg/daily and increasing as needed:

  • Daily Sermorelin Dose: Start at 0.5mg via subcutaneous injections and titrate to up to 2mg/daily, depending on the subject’s response.
  • Frequency: Administer either once in the evening or twice daily. If twice daily, then administer once in the early morning, two hours prior to breakfast, and once in the evening, two hours following the subject’s meal.
  • Study Duration: Up to 16 weeks per course.
  • Notes: Refrain from exceeding 2mg/daily. Alternate injection sites with each application.

Reference Tesamorelin Dosing Protocol

Based on the available clinical data, here's a reference dosage for tesamorelin [18]:

  • Daily Tesamorelin Dose: Start at 1mg/daily and increase to 2mg/daily, depending on the subject’s response.
  • Frequency: Deliver tesamorelin via subcutaneous injection once daily at bedtime.
  • Study Duration: Between 20 to 52 weeks.
  • Notes: Do not surpass 2mg/daily. Rotate injection sites with each application.

Sermorelin vs. Tesamorelin

Where to Buy Research Peptides Online? | 2024 Edition

Sermorelin and tesamorelin are available as reference materials for educational and experimental purposes. Qualified researchers can source them from numerous online vendors. Yet, it’s vital to choose a trusted retailer for safe and efficient research.

Core Peptides

After an in-depth review of the most popular online vendors, we firmly endorse Core Peptides as the top choice for research-grade sermorelin and tesamorelin.

Here's why:

  • Unmatched Purity: Core Peptides ensures product purity of at least 99%, verified through state-of-the-art HPLC-MS testing.
  • Fast Shipping: Researchers can expect their sermorelin and tesamorelin to arrive within 2-3 business days from order confirmation, and enjoy free shipping on orders over $200.
  • US-Made Peptides: All research compounds from Core Peptides adhere to high quality standards, as they are sourced exclusively from certified US manufacturers.
  • Affordable & Discounted Rates: Research peptides such as sermorelin and tesamorelin are affordably priced, with a 5mg sermorelin vial available for $45 and a 10mg tesamorelin vial listed for $79.

Given these advantages, we recommend Core Peptides as a premier provider of top-quality sermorelin and tesamorelin online.

Buy research peptides from Core Peptides today...

Bacteriostatic Water and Research Peptides

Sermorelin and tesamorelin arrive as lyophilized powders that require reconstitution prior to research application. The procedure requires an appropriate solvent that guarantees peptide stability and sterility. Experts typically use bacteriostatic water, containing 0.9% benzyl alcohol added as a preservative.

We suggest obtaining bacteriostatic water and related items from the following premier research materials supplier:

Tesamorelin vs. Sermorelin | Overall

Sermorelin and tesamorelin are two of the more extensively researched GH secretagogues.

They both work by activating the GHRH receptors in the pituitary gland and stimulating pulsatile secretion of GH. By increasing GH, sermorelin and tesamorelin can exert muscle-building and weight-loss effects.

Current research has focused primarily on the fat-burning properties of tesamorelin, while sermorelin has been shown to significantly increase lean mass in male subjects.

Both peptides have been approved by the FDA as safe and effective for specific indications, although sermorelin’s approval was previously withdrawn for commercial reasons.

Qualified professionals looking to conduct research on sermorelin and tesamorelin can acquire them legally from a reputable online supplier.


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  2. Petersenn, S., & Schulte, H. M. (2000). Structure and function of the growth-hormone-releasing hormone receptor. Vitamins and hormones, 59, 35–69.
  3. Yuen KCJ. Growth Hormone Stimulation Tests in Assessing Adult Growth Hormone Deficiency. [Updated 2023 Aug 8]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA):, Inc.; 2000-. Available from:
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  5. Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0 Milligrams Base/Vial, and GEREF (Sermorelin Acetate) Injection, 0.05 Milligrams Base/Amp, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness. (2021). Retrieved 3 June 2021, from
  6. Ferdinandi, E. S., Brazeau, P., High, K., Procter, B., Fennell, S., & Dubreuil, P. (2007). Non-clinical pharmacology and safety evaluation of TH9507, a human growth hormone-releasing factor analogue. Basic & clinical pharmacology & toxicology, 100(1), 49–58.
  7. Stanley, T. L., Chen, C. Y., Branch, K. L., Makimura, H., & Grinspoon, S. K. (2011). Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men. The Journal of clinical endocrinology and metabolism, 96(1), 150–158.
  8. González-Sales, M., Barrière, O., Tremblay, P. O., Nekka, F., Mamputu, J. C., Boudreault, S., & Tanguay, M. (2015). Population pharmacokinetic and pharmacodynamic analysis of tesamorelin in HIV-infected patients and healthy subjects. Journal of pharmacokinetics and pharmacodynamics, 42(3), 287–299.
  9. Falutz, J., Mamputu, J. C., Potvin, D., Moyle, G., Soulban, G., Loughrey, H., Marsolais, C., Turner, R., & Grinspoon, S. (2010). Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in human immunodeficiency virus-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data. The Journal of clinical endocrinology and metabolism, 95(9), 4291–4304.
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  11. Chernecky, C. C., & Berger, B. J. (2012). Laboratory tests and diagnostic procedures. Elsevier Health Sciences.
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  13. Corpas, E., Harman, S. M., Piñeyro, M. A., Roberson, R., & Blackman, M. R. (1992). Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men. The Journal of clinical endocrinology and metabolism, 75(2), 530–535.
  14. Clemmons, D. R., Miller, S., & Mamputu, J. C. (2017). Safety and metabolic effects of tesamorelin, a growth hormone-releasing factor analogue, in patients with type 2 diabetes: A randomized, placebo-controlled trial. PloS one, 12(6), e0179538.
  15. Khorram, O., Laughlin, G. A., & Yen, S. S. (1997). Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women. The Journal of clinical endocrinology and metabolism, 82(5), 1472–1479.
  16. Makimura, H., Feldpausch, M. N., Rope, A. M., Hemphill, L. C., Torriani, M., Lee, H., & Grinspoon, S. K. (2012). Metabolic effects of a growth hormone-releasing factor in obese subjects with reduced growth hormone secretion: a randomized controlled trial. The Journal of Clinical Endocrinology & Metabolism, 97(12), 4769-4779.
  17. Sivakumar, T., Mechanic, O. J., Fehmie, D. A., & Paul, B. T. (2011). Growth hormone axis treatments for HIV‐associated lipodystrophy: a systematic review of placebo‐controlled trials. HIV medicine, 12(8), 453-462.
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  20. Highlights of prescribing information … – for Egrifta. (n.d.). Retrieved September 1, 2023, from
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Scientifically Fact Checked by:

David Warmflash, M.D.

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