Frequently Asked Questions

Which indications have reported and which are still running — organised by how far the evidence has actually travelled, not by what the compound might do.

Which indication sits on which brand's label, what the trials behind them measured, and why a research-market vial carries no indication at all.

The three approved indications, the programme behind each, and what the GIP arm does and does not explain about the results.

The specific injury models the research examined, what a rodent model can and cannot establish, and how a tendon study in rats became “the healing peptide”.

The needle gauge and length commonly used for subcutaneous peptide injection, and the insulin-syringe barrel sizes that pair with them.

Whether insulin syringes are the right tool for subcutaneous peptide injection (yes), the U-100 unit system, and how the markings map to peptide doses.

How the amount of bacteriostatic water sets the concentration (mg ÷ mL), the commonly used range, and a worked 10 mg / 2 mL example — with the math on the calculator.

There is no single correct volume — the water sets the concentration, and the concentration sets the syringe units. The reference table converts vial size and volume into units for the trial dose points.

The volume-to-concentration-to-units arithmetic for the 5 mg and 10 mg vials, tabulated against the labelled dose ladder.

The volume-to-concentration-to-units arithmetic for the 10, 30 and 60 mg vials, tabulated against the labelled ladder — including where a vial cannot hold a dose at all.

The doses the retatrutide trials actually administered — Phase 2's 0.5-12 mg range and the Phase 3 TRIUMPH escalation — and why no approved dosing standard exists.

Why there is no such thing as “the semaglutide dose” — four labels, four ceilings and four different missed-dose rules, each attributed to the label it comes from.

The labelled escalation ladder and its ceiling, why the steps are four weeks apart, and the missed-dose rule as the labels actually write it.

Why no trial-established dose exists, where the 250 and 500 mcg figures actually came from, and what the species extrapolation behind them assumes.

What the FDA Depo-Testosterone label and the 2018 Endocrine Society guideline state about testosterone cypionate injection frequency, and the ~8-day half-life behind the intervals.

What the classic intramuscular testosterone enanthate label, the weekly-subcutaneous Xyosted label, and the 2018 Endocrine Society guideline each state about injection frequency.

Whether testosterone can be injected subcutaneously — the FDA-approved weekly SC product, the intramuscular-only classic labels, and a published SC-vs-IM pharmacokinetic comparison.

What the published onset-of-effects review (Saad et al. 2011) reports about when testosterone therapy's effects appear and peak, domain by domain.

The harmonized normal testosterone reference range (264–916 ng/dL) from Travison 2017 and the Endocrine Society's 264 ng/dL diagnostic threshold — with the caveat that ranges vary by lab and assay.

The 2018 Endocrine Society monitoring schedule for testosterone therapy — testosterone and hematocrit at baseline, 3–6 months, and annually; PSA and a prostate exam for men 40+.

The DHT mechanism behind androgenetic alopecia and why TRT-specific hair-loss outcomes are not quantified in the cited literature — mechanism known, outcome not established.