David DeMesquita's Retatrutide Injection Guide: What He Shows and What You Should Know

This page compares the claims recorded in DeMesquita’s video with published trial evidence. It does not validate the product or demonstrate a clinically tested preparation method. Retatrutide remains investigational; a vial sold as “GLP-3” is not an approved medicine.

This review checks the claims recorded in our existing article against primary research. We could not retrieve an independent transcript for this update, so the quoted wording and timestamps have not been freshly verified.

The "GLP-3" Labeling Problem

"Most bottles will be labeled as GLP-3"

0:00

DeMesquita opens by explaining why the product is labeled "GLP-3" rather than retatrutide:

"Most bottles will be labeled as GLP-3 because it is technically not allowed to be sold right now. It's not FDA approved and Eli Lilly owns a patent so they don't want anyone to sell it."

— David DeMesquita

Retatrutide is not FDA-approved, but changing a label to “GLP-3” or “research use only” does not establish legal status, identity or quality. FDA warns against products sold for human use under research labels and says retatrutide cannot be used in compounding under federal law. The product in this video was not independently tested for this review.

Reconstitution: His Method

"We're going to use bacteriostatic water"

1:01

DeMesquita shows a powder vial, adds bacteriostatic water, chooses a dilution, rolls the vial and recommends refrigeration. Those are observations about his demonstration, not validated retatrutide preparation instructions.

An apparently tidy technique cannot verify identity, potency or sterility. A certificate reporting one test, such as purity, would not by itself validate every aspect of an injectable product either.

His Dosing Compared With Clinical Trials

"I only do 0.5mg per week"

4:22

DeMesquita reveals he uses a notably low dose compared to clinical trials:

"I actually do a split dose. I only do 0.5 milligrams per week. I do a very small amount... I actually got a decent appetite reduction even at low dosages of 1 milligram per week."

— David DeMesquita

The quoted wording mentions both 0.5 mg per week and a split dose. It does not establish a single unambiguous regimen, so this review does not resolve that discrepancy into a dosing instruction. His stated blood-sugar rationale is a personal account, not evidence for treating Graves’ disease with retatrutide.

The Phase 2 obesity trial tested 1 mg weekly and reported 8.7% mean weight loss at 48 weeks, versus 2.1% with placebo, under the efficacy estimand. The earlier 3.19% figure on this page was incorrect for that study. A personal report at 0.5 mg does not establish effectiveness, and the trial result does not validate a grey market product or a split-dose regimen.

Injection Technique

"I take the skin and pull it from my body"

7:37

DeMesquita demonstrates subcutaneous injection around the belly button, using a pinch-and-inject technique:

"I go around the belly button. The left side for me feels way better than my right side... I take the skin and I pull it from my body and then I pop it in."

— David DeMesquita

He also recommends rolling the skin and applying heat for welts. This review found no retatrutide trial evidence validating those measures; persistent or worsening injection-site symptoms need clinical assessment, not an assumed technique fix.

Retatrutide’s published obesity trials used once-weekly subcutaneous injection. They do not establish the claimed half-life advantage over intramuscular injection. Instructions for another medicine or a personal demonstration cannot validate this product’s administration.

Combining Multiple Peptides in One Syringe

DeMesquita mentions combining multiple compounds into a single injection:

"What's in here right now is going to be some retatrutide, HCG, FSH, BPC-157, and TB-500."

— David DeMesquita

He acknowledges that water-based solutions can technically be combined but advises keeping them in separate vials for accurate measurement. The practice of combining multiple peptides in a single syringe is common in the self-administration community but raises several concerns:

• This review found no published compatibility data on retatrutide combined with HCG, FSH, BPC-157, or TB-500 in solution
• Compatibility cannot be inferred because the individual ingredients dissolve in water
• Measurement becomes more complex when several compounds are combined
• Adverse event attribution becomes more difficult when multiple compounds are injected simultaneously

Frequently Asked Questions

Sources

• FDA. Concerns with unapproved GLP-1 drugs.
• DeMesquita, D. (2026). "How to Measure and Inject Retatrutide (GLP-3 Triple Agonist)." YouTube. Watch on YouTube
• Jastreboff, A.M., et al. (2023). Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. New England Journal of Medicine. DOI: 10.1056/NEJMoa2301972
• Eli Lilly and Company. (2025). Lilly's retatrutide achieved significant weight loss and pain relief in adults with obesity and knee osteoarthritis. Press release