Peptide Comparisons
The head-to-head questions everyone asks, answered with mechanisms and data instead of vendor copy.
BPC-157 vs TB-500
These two are less rivals than teammates. BPC-157 is studied for localized, tissue-specific repair — tendons, ligaments, gut lining — with small daily doses. TB-500 works systemically through actin regulation and cell migration, dosed in milligrams once or twice a week. If forced to pick one for a specific tendon issue, community protocols usually start with BPC-157; for widespread soreness or slow general recovery, TB-500. In practice the most common protocol is both together.
Semaglutide vs Tirzepatide
Head-to-head trial data (SURMOUNT-5) gives tirzepatide the edge on raw weight loss — roughly 20% versus 14% body weight over 72 weeks — thanks to its dual GIP/GLP-1 action. Semaglutide counters with a longer safety track record, more prescriber familiarity, and often better availability. Many people also simply respond differently to each: non-responders on one sometimes do well on the other.
Tirzepatide vs Retatrutide
Retatrutide posted the most dramatic weight-loss numbers ever seen in a trial — around 24% at 48 weeks in phase 2 — by adding glucagon receptor activity (energy expenditure) to tirzepatide's GIP/GLP-1 combination. But tirzepatide is an approved medicine with years of real-world safety data; retatrutide is still in trials, so everything circulating outside them is unverified research material. On evidence-to-risk ratio, tirzepatide remains the sane default; retatrutide is the frontier.
BPC-157 vs Pentadeca Arginate (PDA)
Pentadeca Arginate is the same 15-amino-acid sequence as BPC-157 delivered as an arginate salt — it exists primarily because US compounding pharmacies needed a version they could keep offering after the FDA moved BPC-157 onto its bulk-substances difficulty list in 2023. Functionally, community reports and vendor positioning treat them as interchangeable, with identical dosing. If you have legitimate access to one and not the other, that's the deciding factor; there is no evidence either direction that one outperforms.
Ipamorelin vs Sermorelin
They pull the same growth-hormone lever from opposite sides. Sermorelin is a GHRH analog — it whispers to the pituitary through the 'release now' pathway and is the version wellness clinics have prescribed for decades. Ipamorelin is a ghrelin-mimetic secretagogue — a different receptor — prized for triggering a clean GH pulse without cortisol or appetite side effects. Alone, sermorelin is the clinically familiar choice; but the modern standard is ipamorelin combined with a GHRH analog, because hitting both receptors together is synergistic rather than additive.
CJC-1295 DAC vs CJC-1295 (no DAC)
One molecule, two completely different tools. Without DAC (Mod GRF 1-29), half-life is ~30 minutes: you get a sharp, natural-shaped GH pulse, timed to your injection, dosed 100 mcg one to three times daily alongside a secretagogue. With DAC, half-life stretches to about a week: GH sits moderately elevated around the clock — the 'GH bleed' — from a single 1–2 mg weekly shot. Purists favor no-DAC for mimicking physiology; convenience favors DAC. Neither is 'stronger'; they are different shapes of the same exposure.
GHRP-2 vs GHRP-6
GHRP-2 releases somewhat more GH per microgram; GHRP-6 triggers dramatically more hunger through stronger ghrelin mimicry. That hunger is the real decision point: for someone force-feeding a bulk, GHRP-6's appetite surge is a feature; for everyone else it's the reason these are legacy compounds. Both nudge cortisol and prolactin at higher doses — the flaw that ipamorelin was designed to eliminate. In 2026, the honest answer to 'which one?' is usually 'ipamorelin instead,' unless the hunger effect itself is what you're after.
Ipamorelin vs Hexarelin
Hexarelin is the strongest GH secretagogue per microgram in common use — and the least forgiving. It desensitizes its own receptor within weeks of continuous use and measurably bumps cortisol and prolactin. Ipamorelin releases less GH per shot but does it silently and sustainably, cycle after cycle. Unless a protocol has a specific, short-term reason to want maximum pulse amplitude (some research interest centers on hexarelin's cardiac effects), ipamorelin is the rational default.
Semax vs Selank
Same Russian research lineage, opposite temperaments. Semax is the accelerator: an ACTH(4-10) analog studied for focus, processing speed and BDNF elevation — users describe it as stimulating without being a stimulant. Selank is the brake: a tuftsin analog with anti-anxiety effects compared in Russian trials to benzodiazepines, minus sedation and dependence. Pick by your bottleneck — scattered focus points to Semax, anxious rumination points to Selank — and know that many protocols simply alternate: Semax for work hours, Selank for evenings or high-stress days.
PT-141 vs Melanotan II
PT-141 literally descends from Melanotan II — it's a metabolite refined into an FDA-approved drug (Vyleesi) for sexual desire, shedding most of the tanning activity along the way. MT2 remains the tanning compound, with libido effects as a famous side effect and more nausea/flushing baggage. Choose by goal, not potency: tanning → MT2; libido on demand → PT-141. Using MT2 for libido means accepting darkening skin and mole changes as the cost.
AOD-9604 vs HGH Fragment 176-191
These are near-twins: both are the lipolytic tail (176-191 region) of the growth hormone molecule, isolated so fat metabolism comes without GH's growth or glucose effects. AOD-9604 is Fragment 176-191 plus one added tyrosine for stability — and it's the only one of the pair with a human trial history (obesity trials in the 2000s, which showed modest results and were shelved commercially). Practical differences are small; AOD's oral/injectable flexibility and trial data give it the slight edge in credibility, while plain Frag is typically cheaper.
Sermorelin vs Tesamorelin
Both are GHRH analogs, but they live in different evidence classes. Tesamorelin is FDA-approved (Egrifta), with human trials showing real visceral-fat reduction at 2 mg daily — the strongest clinical evidence of any GH-axis peptide. Sermorelin is the affordable clinic staple: decades of prescribing history, flexible dosing, a fraction of the cost, but no comparable outcome trials. If targeting stubborn visceral/abdominal fat with maximum evidence, tesamorelin earns its price. For general GH-axis support on a budget, sermorelin remains the entry point.
Semaglutide vs Retatrutide
Semaglutide is the proven incumbent: approved, widely prescribed, with years of real-world data and roughly 15% average body-weight reduction in trials. Retatrutide is the challenger with the most dramatic phase-2 numbers published to date — around 24% at the top dose — but it remains an investigational compound with no approval anywhere. If the question is 'what has the evidence and the supply chain today', it's semaglutide. Retatrutide's triple-agonist mechanism is why the research community watches it so closely.
Cagrilintide vs Semaglutide
This is a comparison that ends in a partnership. Semaglutide works the GLP-1 incretin pathway; cagrilintide is a long-acting amylin analog working the satiety signal your pancreas co-releases with insulin. Alone, cagrilintide's ~10-11% weight loss doesn't beat semaglutide's ~15%. But because the pathways are complementary, the combination (CagriSema) posted the numbers that made headlines — which is why cagrilintide rarely appears in protocols by itself.
Ipamorelin vs Tesamorelin
They pull the same growth-hormone lever from two different ends. Ipamorelin is a selective GH secretagogue — a clean ghrelin mimetic that triggers a GH pulse with minimal cortisol or appetite effect, dosed in micrograms around bedtime. Tesamorelin is a stabilized GHRH analog with actual human trial data (approved for HIV-associated lipodystrophy) and the strongest evidence for visceral fat reduction of anything in this category. Sleep-and-recovery protocols reach for ipamorelin; visceral-fat-focused protocols reach for tesamorelin.
BPC-157 vs GHK-Cu
Different repair departments. BPC-157 is the tendon-ligament-gut compound: systemic or near-site injections during active injury rehab. GHK-Cu is the remodeling compound: collagen synthesis, wound cosmetics, skin quality and hair — used as much topically as injected. People comparing them usually have an injury (answer: BPC-157) or a skin/anti-aging goal (answer: GHK-Cu); the overlap is mostly in wound healing, where they attack different phases.
Epithalon vs NAD+
Both live on the longevity shelf but bet on different biology. Epithalon is a synthetic pineal tetrapeptide from Russian research lines, associated with telomerase activation and circadian/melatonin normalization — run in short cycles a couple of times a year. NAD+ is a coenzyme your cells burn for repair and energy metabolism that declines with age; injections or infusions try to restore the pool directly, typically as an ongoing practice. Epithalon is the more speculative, lower-cost cycle; NAD+ has broader mainstream research interest but debate about whether injecting the raw molecule is the best way to raise it.
SS-31 vs MOTS-c
Both are 'mitochondrial peptides', but they work different problems. SS-31 (elamipretide) physically stabilizes cardiolipin on the inner mitochondrial membrane — think structural repair of the power plant — and has real human trials in rare mitochondrial diseases. MOTS-c is a mitochondrial-derived signaling peptide that acts like an exercise mimetic through AMPK — think metabolic tuning. Energy/healthspan protocols with an endurance flavor lean MOTS-c; interest in SS-31 tracks the clinical literature on mitochondrial dysfunction.
Tesamorelin vs CJC-1295 DAC
Same receptor, different philosophies. Tesamorelin: daily injections, real human trials, the only GHRH analog with regulatory approval and hard visceral-fat data — at a premium price. CJC-1295 DAC: one or two injections a week thanks to its albumin-binding Drug Affinity Complex, community-priced, but its continuous 'GH bleed' flattens the natural pulse pattern that purists try to preserve. Evidence and pulse fidelity: tesamorelin. Convenience and cost: DAC.
Glutathione vs NAD+
Not competitors — different jobs that wellness clinics happen to sell from the same menu. Glutathione is the body's master antioxidant: detox support, oxidative-stress buffering, and the skin-brightening effect that drives most of its demand. NAD+ is metabolic currency for cellular repair and energy. If the goal is skin tone or recovery from oxidative load, that's the glutathione lane; if it's energy, cognition and ageing metabolism, that's NAD+. Many protocols simply run both.
KPV vs BPC-157
For gut protocols these two split the job: KPV is the anti-inflammatory specialist — a three-amino-acid alpha-MSH fragment studied in colitis models for calming mucosal immune activation. BPC-157 is the repair generalist — protecting and healing the gut lining along with its better-known tendon work. Flare-driven, inflammation-first situations lean KPV; barrier repair and 'leaky gut' framing leans BPC-157. Gut-health stacks very often run both, frequently as oral capsules.
Thymosin Alpha-1 vs TB-500
The most-confused pair in the peptide world: both carry 'thymosin', and they do nothing alike. Thymosin Alpha-1 is an immune modulator — T-cell maturation, used clinically in dozens of countries for hepatitis and as an immune adjunct, with a genuine human evidence base. TB-500 is a fragment of Thymosin Beta-4 used for soft-tissue healing. Immune resilience question → Alpha-1. Injury recovery question → TB-500. The shared surname is an accident of discovery history, not chemistry.
Retatrutide vs Mazdutide
On raw effect size retatrutide leads: ~24% weight loss at 48 weeks in phase 2 versus ~15% for mazdutide at 6 mg in GLORY-1. But mazdutide is the only one of the two that is actually approved anywhere (China, 2025), which means real-world pharmacovigilance data exist for it and not for retatrutide. If the question is 'which is stronger', retatrutide; if it is 'which has cleared a regulator', mazdutide — and the 9 mg mazdutide dose now in trials may narrow the gap.
Survodutide vs Retatrutide
Retatrutide wins on weight loss (~24% vs ~19% in their respective phase 2 trials), but survodutide has the more striking liver data — 83% of MASH patients improved without fibrosis worsening — and is being developed as a liver drug first. Choose the comparison by the problem: fat mass favors retatrutide, fatty liver is where survodutide's evidence is strongest. Both are unapproved and in phase 3.
Ipamorelin vs GHRP-2
GHRP-2 releases more growth hormone per dose; ipamorelin releases it more cleanly. GHRP-2 raises cortisol and prolactin measurably and stimulates appetite, while ipamorelin does almost none of that at standard doses. For anyone whose goals are sleep, recovery and body composition without hormonal side effects, ipamorelin is the modern default. GHRP-2 keeps a niche for people prioritizing maximum GH output or needing the appetite boost.
Kisspeptin-10 vs PT-141
They solve different problems. PT-141 is an on-demand desire drug that works in the brain within an hour and is FDA-approved (as Vyleesi) for low desire in premenopausal women. Kisspeptin-10 works upstream on the hormonal axis — it triggers GnRH, then LH/FSH, then testosterone or estrogen — so its effects are gradual and tied to hormone output. For a single evening, PT-141; for supporting the reproductive axis over weeks, kisspeptin.
IGF-1 LR3 vs PEG-MGF
IGF-1 LR3 is the systemic, whole-body growth signal; PEG-MGF is the local, injury-triggered repair signal. LR3 is dosed daily and raises IGF-1 activity everywhere for hours; PEG-MGF is dosed after training to activate satellite cells in the muscle that was just worked. They are more often sequenced than chosen between — MGF on training days, LR3 on rest days — but as a single choice, LR3 for general anabolism and MGF for a specific lagging or injured muscle.
AOD-9604 vs Tesamorelin
Tesamorelin has the evidence: an FDA approval and trials showing 15–18% visceral fat reduction. AOD-9604 has the theory — a GH fragment meant to burn fat without GH's other effects — but its phase 2 trials in the 2000s failed to show meaningful weight loss and development stopped. Tesamorelin costs more and needs IGF-1 monitoring; AOD-9604 is cheaper and very well tolerated but its fat-loss claim rests on animal data. For stubborn visceral fat with a budget, tesamorelin.