Deep dive comparisons
Long-form breakdowns of the pairs people confuse most, traced to primary sources.
Semaglutide vs Tirzepatide vs Retatrutide
One head-to-head trial, three pivotal trials, and why their headline weight-loss figures are not directly comparable.
GHK vs GHK-Cu
The same sequence, with or without copper: topical trial evidence, formulation caveats and the research-vial market.
Semaglutide vs Liraglutide
In STEP 8, semaglutide produced more weight loss than liraglutide; liraglutide offers generic availability and daily dosing.
Follistatin vs ACE-031
ACE-031 built muscle but was stopped for vascular side effects. Follistatin protein has not been tested by injection in people.
Liraglutide vs Semaglutide vs Tirzepatide vs Retatrutide
One receptor, then two, then three, and the numbers climb with them. Only two of the three steps have a head to head behind them.
HGH vs Sermorelin
Distributing HGH for anti-aging is a federal felony carrying five years. Sermorelin lost to it commercially in 2008 and can still be legally compounded.
IGF-1 LR3 vs IGF-1 DES
Neither has a single published human trial, and sources give LR3's half-life as anywhere from 6 to 30 hours. There is an FDA approved IGF-1, and it is neither of these.
Thymosin Alpha-1 vs LL-37
One is approved in 35 countries and its largest trial found nothing. The other has never been injected in a published study.
Cagrilintide vs Semaglutide
Both were tested in the same trial, in the same people, over the same 68 weeks. Semaglutide won on weight, and the combination beat both while coming in below their sum.
Petrelintide vs Semaglutide
Semaglutide produced 16.9 percent in STEP 1 against petrelintide's 10.7 in ZUPREME-1. Petrelintide's case is tolerability: no vomiting at its best dose, and no added dropouts over placebo.
Semaglutide vs Tirzepatide
Tirzepatide won the head-to-head at 20.2 percent against 13.7. The 47 percent figure everyone quotes is relative; the absolute gap is 6.5 points, from an open-label trial.
Retatrutide vs Tirzepatide
Retatrutide's 28.3 percent is being set against tirzepatide's 22.5 percent. Different trials, different lengths, and no trial yet comparing the two directly.
PT-141 vs Kisspeptin
Both are sold for sex. One works on desire and is FDA approved, the other works on hormones and stops working within two weeks.
MOTS-c vs SS-31
One has an FDA approval and a failed Phase 3. The other has never been given to a person in a published study.
Tesamorelin vs CJC-1295
Two GHRH analogs tested for the same condition. One completed two Phase 3 trials and got approved. The other's Phase 2 was halted in 2006 and never restarted.
Tesamorelin vs HGH
Both are FDA approved. Tesamorelin asks your pituitary for growth hormone and HGH is the hormone itself, and only one is a felony to distribute off-label.
Melanotan I vs Melanotan II
Not two versions of one compound. One is an FDA approved implant for a rare disease, the other is approved nowhere and warned against by four regulators.
Epitalon vs MOTS-c
Two longevity peptides with no published human trial between them. Epitalon's famous human data belongs to a bovine extract, and MOTS-c is something your body already makes.
Glutathione vs NAD+
Both are sold as injections. NAD+ cannot enter cells intact, and a six month trial found oral glutathione raising body stores the injection is meant to fix.
Noopept vs Semax
Two Russian medicines no Western regulator has assessed. Semax is a seven amino acid peptide; Noopept is not a peptide at all.
Semax vs Selank
Same Russian lab, same seven amino acids, built for different problems: Semax for alertness, Selank for anxiety.
GHK-Cu vs Matrixyl
Two topical skin peptides with very different evidence: one carries copper, one carries a fat tail, and Matrixyl 3000, a widely used formulation, is built on the same tripeptide as GHK-Cu.
BPC-157 vs TB-500
Both are sold for tendon and muscle repair. BPC-157's human trials were enemas for ulcerative colitis, and TB-500's trials did not even use TB-500.
BPC-157 vs KPV
BPC-157's Phase 2 results were never published. KPV has no human trial; neither was tested as an injection for the uses it is sold for.
CJC-1295 with DAC vs without DAC
One name, two drugs: one has a measured half-life and three published human trials, the other has never been tested in a person.
Ipamorelin vs CJC-1295
They act on different receptors and are usually sold in the same vial. Each has human trials; the combination everyone buys has none.
MK-677 vs Ipamorelin
Same receptor, a pill against an injection. MK-677 has far more human data, and that is exactly why we know more about what is wrong with it.
KLOW vs GLOW
These are not two products. One contains the other: KLOW is GLOW plus KPV, and neither blend has ever been tested as a blend.
Sermorelin vs Ipamorelin
Two growth hormone peptides sold side by side. One was an approved drug and can still be compounded on prescription. The other was voted down in October 2024.
Enclomiphene vs HCG vs Gonadorelin vs Kisspeptin
Three sit on one hormone chain and the fourth skips it. The one with the best trial evidence was rejected by the FDA in 2015 and abandoned.
Thymosin Alpha-1 vs Thymosin Beta-4 vs TB-500
Two are unrelated proteins sharing a name by accident. The third is seven amino acids taken from the second, and no trial has injected any of them.
NAD+ vs NMN vs NR
Three points on one pathway: compare cellular uptake, human evidence and changing supplement rules.
Sermorelin vs Tesamorelin vs Ipamorelin vs CJC-1295
Three act on the GHRH receptor and one copies ghrelin. Only tesamorelin is approved, and the two with the weakest outcome data were both voted down by the FDA in late 2024.
GLP-1 agonists compared
Twenty compounds act on the GLP-1 receptor. Eight are FDA approved. Most trial doses are not the same thing as a label dose. Here is what separates them.
CT-388 vs Zovaglutide
Weekly dual-receptor CT-388 and monthly GLP-1 zovaglutide have not been compared head to head; their trial results use different measures and follow-up periods.
ACE-031 vs GDF-8
Not two alternatives: ACE-031 is a drug built to neutralise GDF-8, the protein better known as myostatin. One has human trial data; the other is the brake itself.
36 published
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