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
- 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...
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What is Sermorelin?
Physiological GHRH secretion is what primarily regulates the synthesis of growth hormone (GH) in healthy individuals .
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 . Its shorter structure aside, sermorelin has been shown to have a similar half-life to GHRH .
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 :
- 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.
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 .
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 .
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 .
- 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 .
- 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% .
- 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 .
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.
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 .
- 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 .
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 .
- 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 .
- 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 .
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:
Further, one 16-week trial reported transient hyperlipidemia in a patient receiving sermorelin .
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 .
Pooled trial data indicates the following side effects and their incidences :
- 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
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
- 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.
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.
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.
- 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.
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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.