Semaglutide is the incumbent GLP-1 agonist. Retatrutide is the experimental triple agonist that posted 24%+ weight loss in Phase 2 trials. Both are widely available in the Australian peptide market and both are heavily counterfeited.
Semaglutide
Retatrutide
Receptor targets
GLP-1
GLP-1 + GIP + Glucagon
Phase 3 weight-loss result
~15% at 68 weeks
Pending (Phase 2: ~24% at 48 weeks)
Approval status (AU)
TGA approved (Ozempic, Wegovy)
Research only - not approved
Molecular weight
~4114 Da
~4731 Da
Typical research dose
0.25-2.4 mg weekly
2-12 mg weekly
Half-life
~7 days
~6 days
Counterfeit risk in AU
Very high - most-faked peptide in country
High - novelty premium attracts fakes
Identity (LC-MS) expected mass
~4114 Da
~4731 Da
HPLC purity benchmark
≥ 97%
≥ 97%
Verdict
Semaglutide has a decade of approved-pharmaceutical data behind it. Retatrutide is the highest-efficacy weight-loss molecule on the horizon but is still experimental. Both are aggressively counterfeited in the AU grey market - Semaglutide because of demand, Retatrutide because of novelty premium. Verify the mass before reconstituting either.
Frequently asked questions
Is Retatrutide stronger than Semaglutide?
In Phase 2 trials Retatrutide produced ~24% weight loss vs ~15% for Semaglutide. Phase 3 results are pending.
Can the same lab test both?
Yes - LabDoc tests both with the same LC-MS + HPLC workflow. A$549 per vial.
Are they cross-contaminated in production?
It happens. Vendors using the same lyophilisation line for both peptides sometimes ship mixed batches. Identity testing catches it.