Fat loss — peptide, drug, and lifestyle options compared

The most-asked peptide question of the 2020s is some version of "should I take semaglutide?" — and the most useful answer is rarely yes or no. It is: given your starting point, your goal, your timeline, your tolerance for side effects, and your willingness to maintain whatever-you-do for the rest of your life, which intervention has the best evidence-to-effort ratio for you?

The pharmaceutical industry has spent the past five years convincing the culture that GLP-1 agonists are a fat-loss decision. They are not. They are one option on a list that also includes sustained caloric deficit, structured resistance training, sleep and circadian discipline, metformin, an older GLP-1 generation, GH-secretagogue stacks, and (the option no one wants to hear) simply choosing a different goal.

This guide compares the realistic options. It is structured around a load-bearing observation that most fat-loss coverage skips: almost every pharmacological intervention here works while you are taking it and loses most of its effect within 1–2 years after you stop. The cost-benefit question is therefore not "how much fat will I lose" but "what does the post-intervention trajectory look like, and am I prepared to either stay on it or eat the rebound?"

The comparison

Option	Evidence tier	Effect size (relative to placebo, ~52–68 wk)	Time to outcome	Cost / month (US, 2026 est.)	Side effects	Rebound on stop	Who should consider	Who should skip
Sustained caloric deficit + resistance training + sleep discipline	Tier 1 (huge meta-analytic literature)	~5–10% body weight (highly adherence-dependent)	6–24 months	$50–200 (food + gym)	Slow progress; psychological strain; high attrition	None (intervention is the lifestyle)	Almost everyone	No one. Even if doing something else, this is the floor.
Semaglutide (Wegovy / Ozempic)	Tier 1 (STEP 1–5 RCTs)	~14.9% body weight at 68 wk (STEP 1, n=1961)	16–68 weeks	$900–1300 retail; ~$200–400 compounded	GI (nausea ~44%, vomiting ~25%, diarrhea ~30%); pancreatitis (~0.2%); gallbladder events; muscle-mass loss (~20–40% of total weight lost); theoretical thyroid C-cell tumor risk (rodent only)	Substantial — STEP 4 extension showed ~⅔ of lost weight regained within 1 year of discontinuation	BMI ≥27 with comorbidity or BMI ≥30; willing to stay on indefinitely or accept rebound; can tolerate GI; has resistance-training plan to preserve muscle	Cosmetic 5–10 lb loss; unable to tolerate GI; not paired with resistance training; pregnant or planning pregnancy; personal/family MEN-2 or medullary thyroid cancer
Tirzepatide (Mounjaro / Zepbound)	Tier 1 (SURMOUNT 1–4 RCTs)	~20.9% body weight at 72 wk (SURMOUNT-1, n=2539)	16–72 weeks	$1000–1400 retail; ~$300–500 compounded	Similar GI to semaglutide; muscle-mass loss likely similar	Likely similar to semaglutide; SURMOUNT-4 confirmed substantial regain after stop	Same as semaglutide; people who failed semaglutide due to plateau (dual GIP/GLP-1 mechanism produces larger effect)	Same as semaglutide
Older-generation GLP-1 (liraglutide)	Tier 1 (SCALE trials)	~6–8% body weight	16–56 weeks	$500–900 retail	Same GI class effects; daily injection	Substantial; similar pattern	Anyone for whom newer GLP-1s are unaffordable; same indication criteria	Same as newer GLP-1s
Metformin	Tier 2 for fat loss specifically; Tier 1 for diabetes + metabolic syndrome	~2–3 kg vs placebo over 12 months	12–24 weeks	$10–30 (generic)	GI (manageable with titration); rare B12 deficiency on chronic use; lactic acidosis risk in renal impairment	Low — most studies show maintained modest effect on continued therapy	Insulin resistance / pre-diabetes; PCOS; people wanting a modest, durable, cheap adjunct to lifestyle	Anyone expecting GLP-1-magnitude fat loss; renal impairment
Tesamorelin (off-label, US)	Tier 1 for FDA-approved indication (HIV-associated lipodystrophy, ~18% visceral-fat reduction in Falutz 2007 NEJM); Tier 2–3 extrapolated for non-HIV use	~12–18% visceral fat reduction at 26 wk (in trial population)	12–26 weeks	$400–800 compounded; $5000+ branded	Glucose intolerance (~10%), IGF-1 elevation (~47% exceed age-adjusted ceiling), arthralgia, injection-site reaction	Visceral fat regain on discontinuation is consistently reported	People with disproportionate visceral adiposity, normal subcutaneous; willing to monitor glucose + IGF-1	Diabetes; pituitary tumor; pregnancy; anyone seeking subcutaneous fat reduction (this is a visceral-fat compound)
CJC-1295 + Ipamorelin stack	Tier 1 mechanistic (GH-pulse augmentation); Tier 3–4 for fat-loss outcome specifically	Small / variable in non-trial populations; no large RCT for fat-loss endpoint	8–16 weeks	$80–150/month research suppliers	Water retention first 2–4 weeks; transient lethargy; injection-site reaction; IGF-1 elevation	Effect modest enough that "rebound" is the wrong frame	Body-composition recomposition adjunct in someone already lean; sleep + recovery benefits valued separately	Primary fat-loss tool — the GH axis is a recomposition tool, not a fat-loss tool
MK-677 / Ibutamoren	Tier 1 for GH/IGF-1 elevation; Tier 3 for fat-loss outcome (mixed; appetite stimulant effect dominates first 4 weeks)	Variable — often weight gain short-term from water + appetite	4–24 weeks	$50–80 research suppliers	Water retention, appetite spikes, fasting glucose drift, reduced insulin sensitivity on long cycles	Water resolves quickly; metabolic effects may persist	People wanting GH/IGF-1 elevation for muscle preservation, sleep, recovery — not fat loss	Anyone using fat-loss as the primary endpoint; pre-diabetic; long-cycle without breaks
Choosing a different goal	Tier 1 in honesty	Variable	Immediate	$0	None	None	Anyone for whom the fat-loss goal is partly cultural rather than health-driven	People with metabolic indication (T2D, sleep apnea, NAFLD) where intervention is medically warranted

The top row of this table is the load-bearing entry. The last row is the underrated entry. Every middle row is most defensible as an adjunct to the top row, with the understanding that stopping the middle row generally means rebounding most of the lost weight unless the top row is in place.

This guide carries the public comparison. The member continuation walks the per-option evidence, the muscle-loss discussion (the most important and most-skipped conversation in this space), the rebound trajectory in detail, and the founder's view on what to actually do.