Retatrutide Cost: $9.75/mg and $390 per 4-Week Block

Retatrutide cost tracks vial size and nothing else on the listing: 10 mg at $100 divides to $10.00/mg, and 20 mg at $195 divides to $9.75/mg, prices as of September 2026 from the HEEZ catalog. Whole vials, not the per-mg rate, decide what four weeks of material costs. At the 8 mg weekly quantity used in the phase 2 obesity trial (PMID 37366315), four weeks consumes 32 mg, which is two 20 mg vials at $390. There is no pharmacy or insurance price to compare against, because the compound holds no approval anywhere.

What does retatrutide cost per mg by vial size?

Two catalog sizes exist, and the per-mg spread between them is narrow enough that it only matters once you multiply it out. The figures below come from retatrutide price at HEEZ Research, prices as of September 2026 from the HEEZ catalog.

Size	Price	Price per mg
10 mg	$100	$10.00/mg
20 mg	$195	$9.75/mg

Table 1: HEEZ Research retatrutide sizes with cost per mg derived from them. Price per mg = price ÷ size in mg, so $100 ÷ 10 mg = $10.00/mg and $195 ÷ 20 mg = $9.75/mg. Prices as of September 2026 from the HEEZ catalog.

Read that column as a rate for continuous material, which is not how vials are sold. You buy whole units, so the quantity you need gets rounded up to the next vial before any per-mg figure applies, and the rounding is frequently larger than the 25-cent spread between the tiers.

What does a 4-week block cost at each phase 2 weekly amount?

The phase 2 obesity trial ran once-weekly subcutaneous retatrutide at 1 mg, 4 mg, 8 mg and 12 mg against placebo for 48 weeks in 338 adults (PMID 37366315). Those four weekly quantities, multiplied by four weeks, give the material a 4-week block consumes: 1 × 4 = 4 mg, 4 × 4 = 16 mg, 8 × 4 = 32 mg and 12 × 4 = 48 mg.

Weekly amount	mg per 4 weeks	10 mg tier	20 mg tier	Cheaper tier
1 mg	4 mg	1 vial, $100	1 vial, $195	10 mg, by $95
4 mg	16 mg	2 vials, $200	1 vial, $195	20 mg, by $5
8 mg	32 mg	4 vials, $400	2 vials, $390	20 mg, by $10
12 mg	48 mg	5 vials, $500	3 vials, $585	10 mg, by $85

Table 2: cost of a 4-week block at each phase 2 weekly amount (PMID 37366315), computed from the Table 1 catalog prices, September 2026. Vial count = mg per 4 weeks ÷ vial size, rounded up to the next whole vial; cost = vial count × vial price.

The 12 mg row is the one that reverses the per-mg ranking. Forty-eight milligrams at the $9.75/mg rate would be 48 × $9.75 = $468, but 20 mg vials only reach 48 mg by buying 60 mg, so $585 is paid and 60 − 48 = 12 mg sits unused, worth 12 × $9.75 = $117. The 10 mg tier reaches the same 48 mg by buying 50 mg for $500, stranding 2 mg worth 2 × $10.00 = $20. The cheaper rate loses to the coarser increment.

That reversal only appears at quantities that divide badly into 20. At 32 mg the 20 mg tier wins by $10, at 16 mg by $5, and at 4 mg the smaller vial wins outright by $95 because a single 20 mg vial is gross overbuy for that amount. Match the vial size to the weekly quantity before comparing the rate, not after.

One handling point sits against the 12 mg row. A 12 mg weekly amount exceeds a single 10 mg vial, so the cheaper tier at that quantity requires drawing each weekly measurement across two vials at a recorded concentration. The vial-size tradeoff in handling terms, along with the reconstitution arithmetic, is worked through in the retatrutide sourcing guide.

What drives the price of a retatrutide vial?

Analytical coverage, purification depth and how much of the labeled solid is peptide. None are itemized on a listing, so two vials showing the same milligram figure can be different purchases at the same price.

Start with what the certificate of analysis is keyed to. A certificate that names only the compound tells you the seller tests a product line; a certificate carrying the batch number printed on your vial tells you this lot was tested. The second is the only version that supports a purity claim about the material in your hand, and the difference costs the seller real money in per-lot testing, which is part of what a higher price buys.

Purity and identity are separate measurements, and a listing that reports one is not reporting the other. High-performance liquid chromatography gives area percent, meaning the share of detected material that is a single dominant species. It does not say which species. Mass spectrometry answers that by comparing observed mass against the theoretical mass of the sequence. Retatrutide is a synthetic molecule built to act at the GIP, GLP-1 and glucagon receptors together (PMID 41090431), and a synthesis long enough to assemble it accumulates deletion and truncation byproducts that are structurally close to the target. Separating them is the expensive step, so a lower price usually reflects a shorter purification rather than a cheaper coupling.

Then check whether net peptide content is reported at all. Lyophilized material carries counterion, residual solvent and water alongside peptide, so labeled mass is solid mass. If a 20 mg vial is 90% net peptide, it holds 20 × 0.90 = 18 mg of peptide and the real rate is $195 ÷ 18 = $10.83/mg rather than $9.75/mg, an 11.1% increase that no purity percentage would have disclosed. When that figure is absent, treat the per-mg column as a ceiling on value rather than a measurement of it. Material sold on these terms is research use only.

Why is there no insurance or pharmacy price for retatrutide?

Because the registrational trials had not read out. The TRIUMPH program is four phase 3, multicenter, randomized, double-blind studies of weekly subcutaneous retatrutide against placebo alongside diet and physical activity, enrolling over 5800 participants, with type I error controlled at α = 0.05 split between the overarching weight management analysis and each basket trial (PMID 41090431). Without an approval there is no labeled indication, so there is no formulary listing, no copay tier and no prior-authorization path.

That removes the two figures a searcher usually wants. A cash pharmacy price requires a dispensable product, and a covered price requires a payer to have adjudicated one. Neither exists here, which is why every dollar figure attached to retatrutide today is a research-material catalog price rather than a drug price. What separates an approved peptide drug from an investigational one, and why published approval lists disagree, is covered in why approved peptide lists differ.

Is retatrutide cheaper per result than tirzepatide or semaglutide?

That calculation cannot be done from the published record. No head-to-head comparator studies between retatrutide and semaglutide or tirzepatide were running at the time this gap was flagged in the literature, and the absence was described as a major omission in the compound’s development (PMID 37947489). Any cost-per-percentage-point figure comparing them would be dividing results from separate trials with different populations and endpoints.

The two sides are also priced on different systems. Retatrutide carries a research-material price per milligram; the approved agonists carry pharmacy prices per pen or per month set by payers and manufacturers. Comparing those numbers compares two distribution channels, not two compounds. Trial figures for the approved comparators, read on their own terms rather than against retatrutide, sit in 68-week GLP-1 trial results.

How many weeks of material do the endpoints actually require?

Longer than the primary endpoints suggest. The phase 2 obesity trial set percent change in body weight at 24 weeks as its primary endpoint but continued to 48 weeks, and least-squares mean change at 24 weeks was −7.2% at 1 mg, −12.9% at the pooled 4 mg arms, −17.3% at the pooled 8 mg arms and −17.5% at 12 mg, against −1.6% on placebo (PMID 37366315). At 48 weeks the same arms read −8.7%, −17.1%, −22.8% and −24.2%, against −2.1% on placebo.

Within that single trial, the second 24 weeks added 22.8 − 17.3 = 5.5 percentage points at 8 mg and 24.2 − 17.5 = 6.7 points at 12 mg, against 17.3 and 17.5 points in the first 24 weeks. Half the calendar and half the material accounted for 5.5 ÷ 22.8 = 24% of the 48-week figure at 8 mg and 6.7 ÷ 24.2 = 28% at 12 mg. Budgeting material to the 24-week primary endpoint therefore buys the smaller share of the observed effect, and at 8 mg that second half costs another 24 × 8 = 192 mg, or 192 ÷ 20 = 9.6 rounding to 10 vials at $1,950.

A separate phase 2 trial in 281 adults with type 2 diabetes across 42 US centers ran retatrutide at 0.5 mg, 4 mg, 8 mg and 12 mg against placebo and 1.5 mg dulaglutide, with HbA1c change at 24 weeks as the primary endpoint and bodyweight reported at 36 weeks (PMID 37385280). Bodyweight fell 16.94% at 12 mg and 16.81% at the 8 mg slow-escalation arm by week 36, against 3.00% on placebo. Two trials, two durations, and material requirements that differ by a third between them.

One cost driver has nothing to do with vials. Dose-dependent heart rate increases of up to 6.7 beats per minute were reported with retatrutide (PMID 37947489), a monitoring requirement that a 48-week protocol carries whatever the peptide itself costs.

Common questions about retatrutide cost

What is the retatrutide price in the USA? The catalog figures in Table 1 are the domestic landed price. HEEZ Research ships same day by UPS from Florida on orders placed before the 3 PM ET cutoff, at ambient temperature rather than on ice, so lyophilized material carries no cold-chain surcharge on top of the vial price.

Is there a volume discount on retatrutide? No. Both tiers are flat-rate rather than volume-banded, so the gap scales linearly: 100 mg costs 5 × $195 = $975 at the 20 mg tier and 10 × $100 = $1,000 at the 10 mg tier, a $25 difference that stays at 2.5% however much you buy.

Can you return a retatrutide order if the cost was a mistake? No. All sales are final, and supply is restricted to qualified organizations.

Does the price include analytical testing? Yes, on the HEEZ listing. Every lot carries a batch-specific third-party certificate of analysis covering HPLC purity and MS identity, with purity stated as ≥99% as measured, rather than testing being sold as a separate line item.