Frequently Asked Questions

16+ expert answers about peptide research, purity standards, handling, and sourcing.

What is Tesamorelin?

Tesamorelin is an FDA-approved synthetic GHRH analogue (brand name Egrifta). It contains all 44 amino acids of natural GHRH with an N-terminal modification that improves stability. It is approved for reducing excess visceral fat in HIV-associated lipodystrophy.

How does tesamorelin differ from sermorelin?

Both target the GHRH receptor, but sermorelin is a truncated 29-amino-acid fragment while tesamorelin contains all 44 amino acids plus a stabilizing N-terminal modification. Tesamorelin has better bioavailability and a more robust clinical evidence base, having completed Phase III trials.

What research exists on cognitive effects?

Stanley et al. at Massachusetts General Hospital demonstrated tesamorelin improved executive function and verbal memory in healthy older adults. The mechanism may involve GH/IGF-1-mediated neuroprotective effects or indirect benefits from reduced visceral adiposity.

How does Tesamorelin work at the molecular level?

Tesamorelin is a synthetic analogue of human GHRH (growth hormone-releasing hormone) comprising all 44 amino acids of native GHRH with an added trans-3-hexenoic acid moiety at the N-terminus. This modification enhances resistance to DPP-4 enzymatic degradation without altering receptor binding affinity, resulting in improved bioavailability compared to native GHRH.

What research areas has Tesamorelin been studied in?

Tesamorelin has been investigated across 4 primary research areas: Growth Hormone Release, Visceral Adiposity, HIV Lipodystrophy, Cognitive Function. Each area has published preclinical data supporting the peptide's activity through distinct but sometimes overlapping molecular pathways.

What are the most significant research findings for Tesamorelin?

Falutz et al. (2007) demonstrated tesamorelin reduced trunk fat by 15.2% and VAT by 18% over 26 weeks in HIV-associated lipodystrophy in the pivotal Phase III trial. Additionally, stanley et al. (2015) showed tesamorelin improved executive function and verbal memory in cognitively normal older adults with elevated abdominal adiposity.

What dosages of Tesamorelin are used in published research?

The FDA-approved dose is 2 mg subcutaneously once daily. Clinical trials used 1-2 mg daily doses. Diagnostic GH stimulation protocols have also been studied.

How should Tesamorelin be stored and handled in the laboratory?

Store lyophilized powder at -20C. Reconstituted solution should be refrigerated at 2-8C and used within 14 days. Protect from light.

What is the CAS number and molecular weight of Tesamorelin?

The CAS registry number for Tesamorelin is 804475-66-9. The molecular weight is 5135.90 g/mol. The amino acid sequence is: Trans-3-hexenoic acid-Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gl....

What published studies support Tesamorelin research?

Key publications include: Metabolic effects of a growth hormone-releasing factor in patients with HIV Among others, there are 4 peer-reviewed publications cited in our research profile, all indexed in PubMed.

What purity level should I look for when sourcing Tesamorelin?

Research-grade Tesamorelin should be at minimum 98% purity as verified by HPLC analysis. Mass spectrometry should confirm molecular identity. Always request a batch-specific Certificate of Analysis (COA) from an independent third-party laboratory before using any peptide in experiments.

How do I reconstitute Tesamorelin for laboratory use?

Add bacteriostatic water slowly down the inside wall of the vial — never spray directly onto the lyophilized powder. Gently swirl until fully dissolved; the solution should be clear and colorless. Calculate your desired concentration based on the peptide mass and volume of solvent added. Use a sterile syringe and swab the vial stopper with alcohol before each withdrawal.

Is Tesamorelin approved for human use?

No. Tesamorelin is designated Research Use Only (RUO). It is not approved by the FDA for human consumption, veterinary use, or any therapeutic purpose. All references to research findings on this site describe preclinical laboratory studies, not clinical recommendations. Consult a licensed healthcare provider for any medical questions.

How does Tesamorelin compare to CJC-1295 no DAC?

Tesamorelin and CJC-1295 no DAC act through different molecular mechanisms and are studied for overlapping but distinct research applications. Researchers often use both compounds in parallel to compare pathway-specific effects. Detailed mechanism comparisons are available in our research section.

How long does reconstituted Tesamorelin remain stable?

Once reconstituted, Tesamorelin should be stored at 2-8°C (standard refrigerator temperature) and used within 30 days. Lyophilized (unreconstituted) peptide is stable for 12-24 months at -20°C when kept sealed and protected from light. Never refreeze a reconstituted solution, and avoid repeated freeze-thaw cycles.

Where can I source research-grade Tesamorelin?

Research-grade Tesamorelin with 98%+ purity, HPLC verification, and third-party COAs is available at researchvials.com. All peptides ship from the USA with cold-chain packaging to maintain product integrity. This site is an educational resource and does not sell products directly.

General Peptide Research

What are research peptides?

Research peptides are short chains of amino acids — typically between 2 and 50 residues — synthesized for laboratory investigation. They let researchers study receptor binding kinetics, cellular signaling cascades, and enzyme interactions with high specificity. They are not intended for human use.

What does 98%+ purity actually mean for my experiments?

It means HPLC analysis confirmed that at least 98% of the lyophilized powder is your target peptide. The remaining fraction is typically truncated sequences or deletion peptides from synthesis. This matters because impurities can activate off-target pathways and wreck dose-response curves. Mass spectrometry provides the second check, confirming molecular identity.

How should I store peptides long-term?

Keep lyophilized (freeze-dried) vials at -20°C. They are remarkably stable in this form — 12 to 24 months with no significant degradation. Once you reconstitute with bacteriostatic water, move to 2-8°C and use within 30 days. The cardinal rules: no repeated freeze-thaw cycles, protect from light, sterile technique every time you draw from the vial.

What is third-party testing and why does it matter?

It means a lab with zero financial ties to the manufacturer independently verifies identity, purity, and endotoxin levels. This eliminates the obvious conflict of interest in self-testing. The resulting Certificate of Analysis (COA) gives you hard data about what is actually in the vial — not what someone claims is in it.

How do I properly reconstitute a lyophilized peptide?

Swab the vial stopper with an alcohol wipe. Draw your bacteriostatic water into a sterile syringe. Inject slowly down the inside glass wall of the vial — not directly onto the cake of powder, which can denature it. Let it sit for a minute, then gently swirl. Never shake. The solution should be perfectly clear. If it is cloudy, something went wrong.

What does "Research Use Only" mean in practice?

It means the product exists solely for laboratory research — in vitro cell culture work, preclinical animal studies, and educational purposes. RUO compounds have not gone through FDA approval for human safety or efficacy. They cannot legally be sold as drugs, supplements, food additives, or for veterinary use.

How do I read a Certificate of Analysis (COA)?

Look for four things. First, HPLC purity — should be 98%+ with a clean chromatogram showing one dominant peak. Second, mass spectrometry — the observed molecular weight should match the theoretical weight within instrument precision. Third, appearance — should state white or off-white lyophilized powder. Fourth, endotoxin testing — should be below detection limits for injectable-grade material.

Where can I find published peptide research?

PubMed (pubmed.ncbi.nlm.nih.gov) is the gold standard. Search by peptide name, CAS number, or mechanism. Start with review articles — they synthesize the field so you do not have to read 50 primary papers first. Every PMID we cite on this site links directly to the PubMed entry so you can verify our claims.

Where can I source peptides referenced on this site?

This site is purely educational — we do not sell anything. All research peptides referenced here are available at researchvials.com, with 98%+ purity, third-party COAs, and USA-based cold-chain shipping.

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