Tesamorelin Calculator

What Is Tesamorelin?

Tesamorelin is a synthetic analog of human growth hormone-releasing hormone (GHRH). It consists of the full 44 amino acids of native GHRH(1-44), with the N-terminus modified by a trans-3-hexenoic acid group. This modification protects the molecule from rapid enzymatic degradation by dipeptidyl peptidase-4 (DPP-4), substantially extending its biological stability compared to unmodified GHRH. Tesamorelin carries the research designation TH9507 and is known in the pharmaceutical literature under the trade name Egrifta.

Unlike ghrelin-type growth hormone secretagogues such as Ipamorelin, Tesamorelin acts directly on the GHRH receptor in the pituitary gland. It mimics the body's own signal that prompts the somatotroph cells of the pituitary to release growth hormone (GH). Tesamorelin therefore does not introduce growth hormone from outside the body — it amplifies the body's own, pulsatile GH production. This mechanism largely preserves the physiological feedback of the hypothalamic-pituitary axis, which distinguishes Tesamorelin from the direct administration of recombinant GH.

Tesamorelin has been studied most extensively in clinical trials of HIV-associated lipodystrophy, a condition characterized by an accumulation of visceral abdominal fat. The registration trials by Falutz and colleagues demonstrated a meaningful reduction in visceral adipose tissue, making Tesamorelin one of the few GHRH peptides with a robust human clinical dataset. In peptide research, it is discussed primarily for its targeted effect on the visceral fat depot and its well-characterized pharmacokinetics.

Mechanisms of Action

Tesamorelin exerts its biological effects through the GHRH receptor axis and the downstream GH-IGF-1 cascade. The key mechanisms can be summarized as follows:

• GHRH receptor agonism: Tesamorelin binds selectively to the GHRH receptor on the somatotroph cells of the pituitary. This binding activates the cAMP signaling pathway and triggers the synthesis and release of growth hormone, with no need for any exogenous GH supply.
• Preservation of pulsatile GH release: Because Tesamorelin only amplifies the natural releasing signal, the characteristic pulsatile secretion pattern of growth hormone is preserved. The nocturnal GH pulses are increased in amplitude, but the physiological rhythm is not overridden as it would be with constant exogenous GH administration.
• Rise in IGF-1: The increased growth hormone output stimulates the liver to produce insulin-like growth factor 1 (IGF-1). IGF-1 mediates much of the anabolic and tissue-level activity of the GH axis and serves as a central biomarker of efficacy in studies.
• Reduction of visceral adipose tissue: The most pronounced and best-documented effect of Tesamorelin is the selective reduction of visceral abdominal fat (VAT). Growth hormone promotes lipolysis — the mobilization of triglycerides from fat stores — with a particular effect on the metabolically active visceral compartment.
• Maintenance of the feedback loop: Because the hypothalamus can continue to release somatostatin, which restrains GH release, the negative feedback loop remains intact. This limits the risk of excessive GH levels and fundamentally distinguishes Tesamorelin from direct substitution with recombinant growth hormone.
• Metabolic effects: Studies also describe changes in lipid parameters, such as a reduction in triglycerides, and a possible decrease in ectopic liver fat. Effects on insulin sensitivity are dose- and context-dependent and remain an area of ongoing research.

Dosage Calculation

In research settings, Tesamorelin is typically administered subcutaneously once daily, preferably in the evening to support nocturnal GH release. A slow titration ramp is not strictly required, but starting at the lower end of the dose range is a sensible precaution to observe tolerability, particularly potential fluid retention.

Standard Dosing Parameters

• Standard dose: 1 mg per injection, once daily
• Higher range: up to 2 mg per injection in advanced protocols
• Frequency: once daily, preferably before bedtime
• Typical syringe: 0.5 mL insulin syringe (29-31 gauge, 6-8 mm needle)
• Common vial sizes: 10 mg and 20 mg lyophilized powder

Example Calculation: 20 mg Vial with 2 mL BAC Water

A common vial size is 20 mg. Adding 2 mL of bacteriostatic water gives a concentration of 10 mg/mL (10,000 mcg/mL).

• 1 mg dose: 1 ÷ 10 = 0.10 mL (10 units on a U100 syringe)
• 1.5 mg dose: 1.5 ÷ 10 = 0.15 mL (15 units)
• 2 mg dose: 2 ÷ 10 = 0.20 mL (20 units)

At 1 mg per day, a 20 mg vial provides 20 days of dosing (10 days at 2 mg per day). The smaller 10 mg vial reconstituted with 2 mL yields 5 mg/mL (5,000 mcg/mL) and provides ten single 1 mg doses. Use the Tesamorelin calculator above to compute exact volumes for any vial size, reconstitution volume, and target dose.

Injection Site Selection

Tesamorelin is administered subcutaneously into the subcutaneous fat layer, most commonly into the abdomen in the area around the navel. Injection sites should be rotated from day to day to avoid localized irritation and tissue hardening. A very short half-life of roughly 30 minutes means the peptide acts quickly and clears quickly, which is why consistent daily administration is important for a stable research protocol.

Reconstitution

Tesamorelin is supplied as a lyophilized (freeze-dried) powder in sealed vials and must be reconstituted with bacteriostatic water (BAC water) before use. BAC water contains 0.9% benzyl alcohol, which inhibits microbial growth and extends the usable window of the reconstituted solution. Sterile water for injection is not suitable for multi-dose vials because it offers no preservative.

Step-by-Step Reconstitution Protocol

1. Gather supplies: Tesamorelin vial, bacteriostatic water vial, alcohol swabs, a sterile draw needle (18-21 gauge), and your insulin syringe for injection.
2. Wipe the rubber septa of both vials with fresh alcohol swabs and allow to air-dry for about 30 seconds. Do not blow on the septa or touch them after cleaning.
3. Draw the desired volume of BAC water (for example, 2 mL for a 20 mg vial) into the draw syringe.
4. Insert the needle into the peptide vial at an angle, directing the tip toward the inner glass wall rather than the powder cake. A direct stream onto the lyophilized powder can shear peptide bonds and damage the molecule.
5. Slowly push the plunger, allowing the BAC water to run down the inside wall of the vial and gently wet the powder from the side.
6. Gently swirl or roll the vial between your palms until the powder is completely dissolved. The solution should appear clear and colorless. Do not shake or vortex the vial, as shear forces can denature the peptide.
7. Label the vial with the reconstitution date and concentration (e.g., "Tesamorelin 10 mg/mL — reconstituted [date]").

If the solution appears cloudy, discolored, or contains visible particulate matter, discard the vial and do not inject it.

Storage and Shelf Life

• Lyophilized powder (unreconstituted): Store at −20°C for long-term storage, where the powder is stable for many months. Short-term storage at 2-8°C in a refrigerator is acceptable. Keep away from light and moisture and do not leave at room temperature for extended periods.
• Reconstituted solution: Store in the refrigerator at 2-8°C. Tesamorelin is more sensitive once dissolved than more robust peptides, so the solution should be used promptly, typically within about 2 to 4 weeks. Keep the vial upright and away from light, and note the reconstitution date prominently on the label.
• Do not freeze reconstituted peptide. Freeze-thaw cycles cause protein aggregation and loss of activity. Once reconstituted, the vial must remain refrigerated throughout its entire use window.
• Transport: Use an insulated cooler with an ice pack for any travel lasting more than 1-2 hours. Commercial insulated medication pouches maintain 2-8°C for 24-48 hours. Avoid exposure to temperatures above 25°C during transport.

Side Effects and Safety Profile

Tesamorelin has been studied in controlled clinical trials lasting more than a year and showed an overall manageable tolerability profile. However, because its effects are mediated by enhanced growth hormone and IGF-1 activity, the observable effects are closely linked to the known actions of the GH axis. All use remains in the research domain.

Commonly Reported Observations

• Injection site reactions such as redness, itching, mild swelling, or rash. These are among the most commonly documented observations and can be reduced by consistent rotation of injection sites.
• Joint pain (arthralgia), muscle pain, or a feeling of stiffness. This is related to fluid retention in connective tissue and tends to appear earlier in a protocol.
• Fluid retention, which can present as mild peripheral swelling of the hands, ankles, or feet. It is dose-dependent and less pronounced at lower doses.
• Tingling or numbness in the fingers, which can stem from transient nerve compression caused by fluid accumulation (carpal tunnel-like symptoms).

Less Common or Theoretical Concerns

• Effect on glucose metabolism: Growth hormone can reduce insulin sensitivity and influence fasting blood glucose. Individuals with impaired glucose tolerance or diabetes should factor this risk into their assessment.
• IGF-1 levels in the upper range: A sustained elevation of IGF-1 is theoretically significant because IGF-1 promotes cell growth. Close monitoring of IGF-1 values is common in research protocols.
• Fluid-related burden: In predisposed individuals, pronounced water retention could place a strain on the cardiovascular system. High doses increase this theoretical risk.

Contraindications

• Active cancer or a history of malignancy, since increased GH-IGF-1 activity is theoretically unfavorable
• Pituitary disorders, recent pituitary surgery, or radiation to the head region
• Pregnancy and breastfeeding (insufficient safety data)
• Known hypersensitivity to Tesamorelin, mannitol, or any other component of the preparation

At standard research doses, Tesamorelin was described as largely well tolerated in the registration trials. Nonetheless, given its effect on the endocrine GH axis, caution is warranted and consultation with a qualified healthcare provider is strongly recommended.

Combinations and Stacks

Tesamorelin Within the GHRH Class

Tesamorelin belongs to the family of GHRH analogs and is closely related functionally to Sermorelin and CJC-1295 (no DAC). All three stimulate the same GHRH receptor but differ in stability and duration of action. Sermorelin corresponds to the shorter GHRH(1-29) fragment, CJC-1295 without DAC is a modified fragment with improved stability, and Tesamorelin is a fully stabilized GHRH(1-44) analog with the most extensive clinical evidence base for visceral fat reduction.

Tesamorelin + Ipamorelin — The GHRH-plus-GHRP Approach

A widely used concept in research combines a GHRH analog with a GHRP (growth hormone releasing peptide) such as Ipamorelin. The two peptides act through distinct, complementary receptors:

• Tesamorelin amplifies the releasing signal at the GHRH receptor and increases the amplitude of the GH pulses.
• Ipamorelin acts on the ghrelin receptor and additionally dampens the inhibitory action of somatostatin, allowing a larger fraction of the available GH reserve to be released.
• The combined stimulus on both axes produces a more pronounced GH response in models than either peptide achieves alone, without abolishing the pulsatile pattern.

Because such a combined stimulus places greater demand on the GH-IGF-1 axis, research protocols typically favor conservative doses, careful monitoring of glucose and IGF-1, and planned breaks.

Tesamorelin as a Standalone

Owing to its specific clinical profile — the targeted reduction of visceral adipose tissue — Tesamorelin is often used as a standalone compound in research rather than being stacked. Its clearly defined endpoint of visceral fat reduction makes it a readily studyable single peptide with unambiguous biomarkers such as IGF-1 and VAT measurement.

Research-grade Tesamorelin is available directly from BergdorfBio: Tesamorelin at BergdorfBio.

Frequently Asked Questions

How does Tesamorelin differ from growth hormone (HGH)?

Tesamorelin is not growth hormone — it is a GHRH analog. It prompts the pituitary to release more of the body's own growth hormone, whereas HGH supplies the hormone directly from outside the body. The key difference lies in feedback: with Tesamorelin, the inhibitory action of somatostatin is preserved, so GH levels cannot rise without limit. In addition, the natural pulsatile secretion pattern of growth hormone is maintained, which is not the case with constant HGH administration.

Why is Tesamorelin injected in the evening?

The body's largest natural GH release occurs during the first hours of deep sleep. An evening injection of Tesamorelin is intended to amplify this physiological pulse rather than create an additional, off-rhythm GH surge. The very short half-life of roughly 30 minutes fits this concept well, since the signal remains tightly time-limited.

How quickly are effects expected?

IGF-1, used as a biomarker, rises measurably within the first days to weeks. The structural changes — in particular the reduction of visceral adipose tissue — develop considerably more slowly. In the registration trials, significant changes in visceral abdominal fat were typically documented only after several months of continuous use.

Should Tesamorelin be used in a fasted state?

Because growth hormone and insulin act in partly opposing ways, a high insulin level after a carbohydrate-rich meal dampens the GH response. Research protocols therefore often suggest spacing the injection some time away from the last large meal. With an evening administration before bed, this gap often arises naturally.

Does Tesamorelin affect blood sugar?

Growth hormone can reduce insulin sensitivity, so Tesamorelin can influence fasting blood glucose and glucose tolerance. In studies, these effects were generally moderate and dose-dependent. Monitoring glucose values is sensible for longer research protocols, particularly in individuals with pre-existing insulin resistance.

Is post-cycle therapy (PCT) required?

Tesamorelin does not act on the hypothalamic-pituitary-gonadal axis and does not suppress the body's own testosterone production. A classic PCT, of the kind common after androgenic compounds, is therefore not required. Because Tesamorelin merely amplifies the natural GHRH signal, the pituitary generally recovers after discontinuation without further intervention.

Is Tesamorelin prohibited in drug testing?

Yes. As a growth hormone-releasing factor and GH secretagogue, Tesamorelin falls under the WADA prohibited list and is banned in sport both in-competition and out-of-competition. Athletes subject to WADA-compliant testing should treat Tesamorelin as a prohibited substance and verify the applicable anti-doping rules before any use.

Can Tesamorelin be mixed with Ipamorelin in the same syringe?

Some research protocols combine a GHRH analog and a GHRP in a single syringe immediately before injection. In general, however, it is safer to reconstitute each peptide individually and inject them separately, since their combined stability in solution is not well characterized. Separate injections at adjacent sites add minimal inconvenience and eliminate the risk of dosing errors.

Where can I buy Tesamorelin?

BergdorfBio offers research-grade Tesamorelin with verified purity and concentration. View the product page: Buy Tesamorelin at BergdorfBio. All products are sold strictly for research purposes.

Medical Disclaimer: The information on this page is provided for educational and research purposes only. Within the context of this offering, Tesamorelin is not an approved drug or medical treatment and is sold strictly for research use. Nothing on this page constitutes medical advice, diagnosis, or a recommendation to use any specific compound. Always consult a qualified healthcare professional before beginning any peptide protocol. BergdorfBio assumes no liability for the use or misuse of the information presented here.