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Tesamorelin dose calculator

Convert any Tesamorelin dose into syringe units in real time, pre-filled with a 5 mg / 2 mL example.

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Draw on a U-100 syringe

40.0 units

Volume to draw

0.400 mL

Tesamorelin is a daily injection people use specifically to reduce stubborn deep belly fat (visceral adipose tissue). It's an analog of growth hormone-releasing hormone (GHRH) that prompts the pituitary to release more of the body's own GH. In FDA trials for HIV-related lipodystrophy, daily 2 mg injections reduced visceral fat by about 15–18% over 26 weeks. This page covers reconstitution math and daily dose logging.

How the Tesamorelin dose calculator works

This calculator answers a simple question: given the concentration of the Tesamorelin solution already in your vial, how many syringe units does today's dose work out to? It is the second half of the reconstitution math — the first half locks in concentration, this one converts any dose mg or mcg into a clean unit count.

The formula is volume in mL equals dose mg divided by concentration mg/mL, then volume times one hundred to get units on a U-100 insulin syringe. With a 2.5 mg/mL Tesamorelin solution and a 1 mg dose, the draw is 0.40 mL or about 40 units. Type any other dose and the unit count updates in real time — no spreadsheets, no guesswork.

Inputs that genuinely matter: concentration (which only changes when you reconstitute a new vial) and dose mass. Syringe type matters too, but only because U-100 vs U-40 changes the multiplier — almost every modern insulin syringe is U-100, which is why the math defaults to that. Edge cases worth flagging: switching from mcg to mg without checking the input unit, or carrying yesterday's unit count over to a new vial that was reconstituted with a different volume of BAC water.

Most people use this calculator at two moments: when titrating a dose up or down, and when prepping a single dose before injection. The output is meant to be checked against the syringe before drawing — read the markings, confirm the unit count, then draw. The calculator is fast precisely so you can do that check every time without it feeling like a chore.

How Tesamorelin dosing is tracked

Protocols documented in published research on Tesamorelin typically involve a daily administration cadence, scheduled for seven days per week. The studied dose is substantial, frequently specified at 1 mg or 2 mg per day, which requires a much larger injection volume compared to GHRH fragments dosed in micrograms. For a 1 mg dose, drawing from a moderately concentrated vial requires careful measurement, often with a standard 1 mL U-100 insulin syringe to ensure accuracy for volumes that can be 40 units or more.

In a departure from the common evening schedule for many GH secretagogues, clinical trials for Tesamorelin predominantly utilized a morning-dosing schedule. The rationale is linked directly to its extended half-life; since the peptide provides a sustained GHRH signal, it is not necessary to time its administration to coincide with the primary natural growth hormone pulse during sleep. This morning administration pattern is a well-documented characteristic of the protocols established during its clinical development for its approved indication.

The structural stability of tesamorelin directly informs the administration schedules observed in research literature. Its resistance to DPP-IV degradation permits a daily dosing cadence, which allows for sustained engagement of the GHRH receptor. This contrasts sharply with native GHRH, which would require much more frequent administration to achieve a similar exposure profile. When planning documentation for a research project, this daily cadence is a key parameter to schedule and record. For calculation purposes, a 5 mg vial reconstituted with 2 mL of diluent contains 2.5 mg per mL. A 1 mg illustrative dose is therefore calculated as 0.4 mL or 40 units on a standard U-100 insulin syringe, often documented on a daily cadence.

Tesamorelin mechanism in plain English

Tesamorelin functions by binding to and activating the growth hormone-releasing hormone receptor (GHRHR), located on somatotroph cells in the anterior pituitary gland. This is the identical pathway used by endogenous GHRH to stimulate the synthesis and pulsatile secretion of growth hormone. The critical distinction lies in its metabolic stability; while natural GHRH and unmodified analogs like sermorelin are quickly cleaved and inactivated by the enzyme dipeptidyl peptidase-4 (DPP-IV), Tesamorelin's trans-3-hexenoyl modification sterically hinders this process. This resistance to breakdown extends its plasma half-life, allowing for prolonged GHRHR stimulation from a single dose.

The primary mechanism differentiating tesamorelin from native GHRH lies in its resistance to enzymatic breakdown. Endogenous GHRH is rapidly inactivated by the enzyme dipeptidyl peptidase IV (DPP-IV), which cleaves the peptide bond between the first two amino acids, Tyr1 and Ala2. Tesamorelin is engineered to prevent this. The trans-3-hexenoyl moiety, a six-carbon acyl group, is covalently bonded to the N-terminal tyrosine. This chemical shield sterically hinders the DPP-IV enzyme, physically blocking its access to the cleavage site. This protection results in a substantially longer plasma half-life, enabling the molecule to circulate and interact with GHRH receptors in the pituitary for an extended duration.

Common Tesamorelin dose mistakes

  • Assuming the per-dose volume and syringe draw will be as small as sermorelin's and failing to plan for a larger subcutaneous injection.
  • Neglecting to systematically document and rotate injection sites, which can lead to localized lipohypertrophy that interrupts a planned daily schedule.
  • Mistaking the typical milligram (mg) dose for micrograms (mcg) in the calculator, leading to a thousand-fold dosing error.
  • Attempting to reconstitute a 5 mg vial with an excessively small diluent volume, making the large 1 mg dose difficult to measure and draw accurately.
  • Administering the daily dose in the evening by default, contrary to the morning administration schedule used in the vast majority of published clinical trials.
  • Mistaking the trans-3-hexenoyl modification for a simple carrier or delivery system, rather than the specific chemical shield it is.
  • Failing to distinctly log the molecule as tesamorelin, instead using the generic term 'GHRH', which obscures the critical stability difference in protocol review.
  • Neglecting to record whether the tracked material is the pharmaceutical product Egrifta or a research-grade compound, a distinction vital for data integrity.

Frequently asked questions about Tesamorelin dose

Why is the Tesamorelin dose in milligrams (mg) when other GHRH analogs are often dosed in micrograms (mcg)?
Tesamorelin's milligram-level dosing is a function of its molecular structure and the extensive clinical research that established its use profile. As the full 44-amino-acid GHRH sequence, its molecular weight and receptor affinity necessitate a larger mass to achieve the desired level of pituitary stimulation. The protocols for its FDA-approved indication were developed around a 1 mg or 2 mg daily dose, reflecting its distinct pharmacology compared to smaller, truncated peptide fragments.
What specifically is the purpose of the trans-3-hexenoyl group on Tesamorelin?
The trans-3-hexenoyl group is a fatty acid-based modification chemically bonded to the start of the peptide chain. Its sole purpose is to serve as a physical shield, sterically hindering the enzyme DPP-IV from accessing its cleavage site on the GHRH sequence. This protection from enzymatic degradation is what grants Tesamorelin a significantly longer half-life compared to native GHRH, which is its primary design advantage.
Using a 5 mg vial reconstituted with 2 mL of water, how many units would a 1 mg dose be?
When a 5 mg vial is reconstituted with 2 mL of bacteriostatic water, the solution's final concentration is 2.5 mg/mL. To obtain a 1 mg dose from this solution, you would need to draw 0.40 mL. On any standard U-100 insulin syringe, a volume of 0.40 mL is equivalent to exactly 40 units.
Why is tracking injection site rotation especially important for Tesamorelin?
The emphasis on site rotation is a direct consequence of its common protocol: daily administration combined with a relatively large dose volume. Delivering a volume of 0.4 mL (40 units) or more into the same subcutaneous tissue spot every day increases the risk of lipohypertrophy, a benign but palpable thickening of fat tissue. This can alter absorption rates and impact comfort, making the careful logging and rotation of sites an important variable to monitor for consistent administration.
Can Tesamorelin be considered a longer-lasting version of sermorelin?
While both peptides activate the GHRH receptor, they are fundamentally different molecules. Sermorelin represents only the first 29 amino acids of the GHRH sequence. Tesamorelin is the full 44-amino-acid sequence and includes an additional protective modification. This structural difference gives Tesamorelin a much longer half-life and leads to different studied protocols with larger dose magnitudes.
Why was Tesamorelin studied with morning, rather than evening, administration?
The morning administration schedule seen in most clinical literature is tied to Tesamorelin's extended half-life. Because it resists rapid breakdown and provides a prolonged GHRH signal for many hours, it does not need to be timed to coincide with the body's primary nocturnal growth hormone pulse. A morning dose provides a sustained level of GHRH receptor stimulation throughout the day, a profile that was extensively studied and established for its approved indication.
What is the concrete chemical difference between tesamorelin and native GHRH?
Tesamorelin is the full 44-amino-acid sequence of human GHRH with one specific chemical modification. A trans-3-hexenoyl group is covalently attached to the N-terminal tyrosine residue. This addition serves to protect the molecule from rapid degradation by the DPP-IV enzyme, which is what gives tesamorelin a significantly longer half-life compared to unmodified, endogenous GHRH.
What is the difference between Tesamorelin and Egrifta for logging purposes?
The active molecule is identical; tesamorelin is the generic name for the peptide, and Egrifta is the brand name for the FDA-approved pharmaceutical product. The key difference for logging is the source and standardization. Egrifta comes in a fixed-dose kit with verified purity, while material labeled as 'tesamorelin' is typically for research purposes and may have different purity and handling considerations. It is critical to document which form is being studied for accurate record-keeping.
Why is the DPP-IV enzyme unable to cleave tesamorelin?
The DPP-IV enzyme is prevented from cleaving tesamorelin due to steric hindrance. The enzyme's active site must physically access the peptide bond between the first and second amino acids (Tyr1-Ala2) to break it. The bulky trans-3-hexenoyl group attached at the N-terminus acts as a physical shield, blocking the enzyme's approach. This structural defense preserves the full-length peptide, allowing it to remain active in plasma for much longer.

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