Peptide blends: working out each component's dose
Last updated: October 3, 2026 · 11 min read · By the Grey Peptides Editorial Board
- Each component's concentration is its milligrams times 1,000, divided by the millilitres of water added. On a U-100 syringe, 10 units is 0.1 mL. Everything else follows from those two lines.
- You cannot dose one component of a blend on its own. Any draw chosen for one component delivers every other component in the vial's fixed ratio, and the heaviest component dominates.
- There is no evidence-based dose for any blend: none has been tested as a blend, and for most components FDA says it has little or no human safety information. The arithmetic tells you what is in a draw, not whether it is wise.
The two lines of arithmetic
Blend maths looks intimidating because the vial lists several numbers, but every calculation rests on two lines. First, the concentration of each component in micrograms per millilitre is its labelled milligrams multiplied by 1,000, divided by the millilitres of water you add. Second, on a U-100 insulin syringe, 100 units is 1 mL, so 10 units is 0.1 mL and 20 units is 0.2 mL. Multiply the concentration by the volume you draw and you have the micrograms of that component in the draw. Our Blend Calculator does exactly this, and every number on this page comes from its engine.
Take the four-peptide composition often sold as a 'KLOW'-type vial: 50 mg of GHK-Cu with 10 mg each of BPC-157, TB-500 and KPV. Add 2 mL of water and the GHK-Cu concentration is 50 × 1,000 / 2 = 25,000 mcg per mL, and each of the others is 5,000 mcg per mL. A 10-unit draw, 0.1 mL, therefore contains 2,500 mcg of GHK-Cu and 500 mcg of each of the other three. Add 3 mL instead and the same 10 units holds 1,667 mcg of GHK-Cu and 333 mcg of each of the rest 1.
Why one component always drags the others along
A blend is a fixed-ratio mixture. Whatever volume you draw, every component comes out in the proportion it went in. In the four-peptide vial, GHK-Cu is 62.5% of the total peptide mass, so any draw chosen to deliver a particular amount of BPC-157 also delivers five times as much GHK-Cu 1. Changing the water changes how much is in each unit, not the ratio; only a different vial changes the ratio. The Blend Calculator's explainer calls this the ratio trap.
The trap is easiest to see where one component has a labelled dose. Tesamorelin is an approved drug; the EGRIFTA WR label's dose is 1.28 mg once daily 2. In a 10 mg vial of tesamorelin and ipamorelin, 5 mg each, made up with 2 mL, reaching 1,280 mcg of tesamorelin takes a 51.2-unit draw, and that draw also delivers 1,280 mcg of ipamorelin, a peptide that has never been approved and whose one efficacy trial failed 1 3. The vial holds only 3 such draws of tesamorelin. The blend decides the ipamorelin dose for you.
The same arithmetic applies to the cagrilintide-semaglutide composition. Semaglutide's approved weight-management label starts at 0.25 mg weekly 4; in a 5/5 mg vial made up with 2 mL, a draw giving 250 mcg of semaglutide is 10 units, and it carries 250 mcg of cagrilintide 1. In the CagriSema trials the two were given as separate, matched doses on their own escalation schedule, between 0.3 and 2.4 mg of cagrilintide weekly 5, and a vial sold as this blend is neither the trial product nor an approved drug 6.
How long a vial lasts, and what a wrong label does
Because every component sits in the same liquid, they all run out at the same moment: the vial is empty when the water is gone, whatever the ratio. In the four-peptide vial made up with 2 mL, 10-unit draws give 20 draws in total, and each of the four components is used up on the last one 1. Adding more water gives more draws but less of everything in each, so the total delivered from the vial never changes. That is a useful check on any schedule someone proposes: the number of draws multiplied by the micrograms per draw must equal what the label says the vial contains.
All of this assumes the label is right, and for products outside the regulated supply that is a large assumption. When researchers bought semaglutide vials from illegal online pharmacies and measured them, the semaglutide content exceeded the labelled amount by 28.6% to 38.7%, while measured purity was far below the 99% claimed 7. A blend that is 30% over-strength delivers 30% more of every component in every draw, and no arithmetic done on the label can reveal it. The calculator can only be as accurate as the numbers you type into it.
Three mistakes the arithmetic catches
Reading the total as the dose. A vial labelled '80 mg' is 80 mg of peptide in total, not 80 mg of anything in particular. Dividing the total by the water gives a combined concentration, which is meaningless for any single component. Work component by component.
Changing the water and keeping the units. Doubling the water halves the amount of every component in each unit. Someone who reconstituted the last vial with 2 mL and this one with 3 mL, and keeps drawing the same number of units, gets two-thirds as much of everything. The tables below show both volumes side by side for that reason.
Confusing units with millilitres or milligrams. Units on a U-100 syringe are hundredths of a millilitre, nothing more. They are not milligrams, not 'IU', and they mean nothing until multiplied by a concentration. Our guide to insulin syringe units covers the markings.
Reference tables for six common compositions
These tables give, for each composition, the concentration of every component and what 10 and 20 units deliver, at 2 mL and 3 mL of water, computed by the Blend Calculator's engine on October 3, 2026 1. They are generic compositions named by their contents, not products; labels vary, so the calculator lets you enter what your own vial states 6. A draw size shown here is an arithmetic example, not a recommended dose.
GHK-Cu, BPC-157, TB-500 and KPV, 80 mg (50/10/10/10)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | GHK-Cu | 25,000 | 2,500 | 5,000 | 62.5% |
| 2 mL | BPC-157 | 5,000 | 500 | 1,000 | 12.5% |
| 2 mL | TB-500 | 5,000 | 500 | 1,000 | 12.5% |
| 2 mL | KPV | 5,000 | 500 | 1,000 | 12.5% |
| 3 mL | GHK-Cu | 16,667 | 1,667 | 3,333 | 62.5% |
| 3 mL | BPC-157 | 3,333 | 333 | 667 | 12.5% |
| 3 mL | TB-500 | 3,333 | 333 | 667 | 12.5% |
| 3 mL | KPV | 3,333 | 333 | 667 | 12.5% |
A four-peptide composition sold under several brand names. No study has tested it as a blend.
GHK-Cu, BPC-157 and TB-500, 70 mg (50/10/10)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | GHK-Cu | 25,000 | 2,500 | 5,000 | 71.4% |
| 2 mL | BPC-157 | 5,000 | 500 | 1,000 | 14.3% |
| 2 mL | TB-500 | 5,000 | 500 | 1,000 | 14.3% |
| 3 mL | GHK-Cu | 16,667 | 1,667 | 3,333 | 71.4% |
| 3 mL | BPC-157 | 3,333 | 333 | 667 | 14.3% |
| 3 mL | TB-500 | 3,333 | 333 | 667 | 14.3% |
A three-peptide composition sold under several brand names. No study has tested it as a blend.
BPC-157 and TB-500, 20 mg (10/10)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | BPC-157 | 5,000 | 500 | 1,000 | 50.0% |
| 2 mL | TB-500 | 5,000 | 500 | 1,000 | 50.0% |
| 3 mL | BPC-157 | 3,333 | 333 | 667 | 50.0% |
| 3 mL | TB-500 | 3,333 | 333 | 667 | 50.0% |
No study has tested this pair in people, blended or separately.
TB-500, BPC-157 and KPV, 45 mg (25/10/10)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | TB-500 | 12,500 | 1,250 | 2,500 | 55.6% |
| 2 mL | BPC-157 | 5,000 | 500 | 1,000 | 22.2% |
| 2 mL | KPV | 5,000 | 500 | 1,000 | 22.2% |
| 3 mL | TB-500 | 8,333 | 833 | 1,667 | 55.6% |
| 3 mL | BPC-157 | 3,333 | 333 | 667 | 22.2% |
| 3 mL | KPV | 3,333 | 333 | 667 | 22.2% |
A three-peptide composition sold under a brand name (v44: added from the Name Decoder's October 1, 2026 listing review). No study has tested it as a blend.
CJC-1295 (no DAC) and ipamorelin, 10 mg (5/5)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | CJC-1295 (no DAC) | 2,500 | 250 | 500 | 50.0% |
| 2 mL | Ipamorelin | 2,500 | 250 | 500 | 50.0% |
| 3 mL | CJC-1295 (no DAC) | 1,667 | 167 | 333 | 50.0% |
| 3 mL | Ipamorelin | 1,667 | 167 | 333 | 50.0% |
No study has tested this pair in people.
Tesamorelin and ipamorelin, 10 mg (5/5)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | Tesamorelin | 2,500 | 250 | 500 | 50.0% |
| 2 mL | Ipamorelin | 2,500 | 250 | 500 | 50.0% |
| 3 mL | Tesamorelin | 1,667 | 167 | 333 | 50.0% |
| 3 mL | Ipamorelin | 1,667 | 167 | 333 | 50.0% |
Tesamorelin is approved alone (EGRIFTA) for HIV-associated abdominal fat; this blend is not approved and has not been studied.
Cagrilintide and semaglutide, 10 mg (5/5)
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | Cagrilintide | 2,500 | 250 | 500 | 50.0% |
| 2 mL | Semaglutide | 2,500 | 250 | 500 | 50.0% |
| 3 mL | Cagrilintide | 1,667 | 167 | 333 | 50.0% |
| 3 mL | Semaglutide | 1,667 | 167 | 333 | 50.0% |
Semaglutide is approved alone; the cagrilintide-semaglutide combination (CagriSema) is investigational, and a vial sold as this blend is neither the trial product nor approved.
Melanotan II and PT-141, 20 mg (10/10), example composition
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | Melanotan II | 5,000 | 500 | 1,000 | 50.0% |
| 2 mL | PT-141 | 5,000 | 500 | 1,000 | 50.0% |
| 3 mL | Melanotan II | 3,333 | 333 | 667 | 50.0% |
| 3 mL | PT-141 | 3,333 | 333 | 667 | 50.0% |
An example pairing (v45, Q294): the two are usually sold as separate 10 mg vials and combined by the user; we found no premixed listing on October 3, 2026. PT-141 is approved alone (Vyleesi); melanotan II is unapproved; no study has tested the pair.
SS-31 and MOTS-c, 20 mg (10/10), example composition
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | SS-31 | 5,000 | 500 | 1,000 | 50.0% |
| 2 mL | MOTS-c | 5,000 | 500 | 1,000 | 50.0% |
| 3 mL | SS-31 | 3,333 | 333 | 667 | 50.0% |
| 3 mL | MOTS-c | 3,333 | 333 | 667 | 50.0% |
An example composition (v45, Q313); we did not verify a premixed listing. SS-31 is approved alone only as Forzinity for Barth syndrome; MOTS-c is unapproved and named on the WADA list; no study has tested the pair.
Selank, pinealon and PE-22-28, 15 mg (5/5/5), example composition
| Water added | Component | Per mL (mcg) | Per 10 units (mcg) | Per 20 units (mcg) | Share of vial |
|---|---|---|---|---|---|
| 2 mL | Selank | 2,500 | 250 | 500 | 33.3% |
| 2 mL | Pinealon | 2,500 | 250 | 500 | 33.3% |
| 2 mL | PE-22-28 | 2,500 | 250 | 500 | 33.3% |
| 3 mL | Selank | 1,667 | 167 | 333 | 33.3% |
| 3 mL | Pinealon | 1,667 | 167 | 333 | 33.3% |
| 3 mL | PE-22-28 | 1,667 | 167 | 333 | 33.3% |
An example composition (v45, Q313); we did not verify a premixed listing. None of the three is approved in the US; no study has tested the combination.
Why there is no 'blend dose'
People search for a KLOW, GLOW or Wolverine dose as if one existed. None does. No blend on this page has been tested as a blend in any study 6. For most of the components on their own, the human evidence is missing too. FDA's risk statements say compounded BPC-157, the thymosin beta-4 fragment sold as TB-500, KPV and injectable GHK-Cu may pose a risk of immunogenicity, and that the agency has no or only limited human safety information, or none at all for KPV and the TB-500 fragment; for CJC-1295 it lists serious adverse events including increased heart rate and a systemic vasodilatory reaction; for ipamorelin, serious adverse events including death when it was given intravenously in a study 8.
So any number of units someone suggests for a blend is a number someone chose, not a dose anyone measured. Combining components also makes it impossible to tell which one caused a side effect, a point our article on serious reactions to injected peptides makes with a real case. And the arithmetic assumes the label is right; testing of gray-market vials has found content and purity far from what was claimed, as our guide to what a COA rarely shows describes.
Blends versus separate vials
The alternative to a blend is a stack: separate vials, each measured on its own. That removes the ratio trap, because each component can be drawn independently, but it multiplies everything else, from labels to trust to draws to get right, and it does nothing about the missing evidence 6. Our KLOW vs GLOW vs Wolverine comparison sets out what is in each named blend and what is known about each component, and the blends hub collects every blend page on the site.
Frequently asked questions
How do I calculate the dose of each peptide in a blend?
Concentration of each component equals its mg times 1,000, divided by the mL of water added; multiply by the volume drawn (10 units on a U-100 syringe is 0.1 mL). Our Blend Calculator does this for every component at once.
Can I dose just one peptide from a blend?
No. A blend is a fixed ratio, so any draw delivers every component in the same proportion. Only a vial with a different composition, or separate vials, changes that.
What is the KLOW peptide dosage?
There is none with evidence behind it. No study has tested KLOW-type blends, and FDA says it has little or no human safety information for most of the components.
How many draws are in a blend vial?
Divide the water added by the volume of each draw: 2 mL drawn 10 units (0.1 mL) at a time gives 20 draws. Every component runs out on the same draw, because they share the same liquid.
Does adding more water change the ratio?
No. More water lowers the amount of every component per unit by the same factor; the ratio between components stays the same.
Related on Grey Peptides
Sources
- Grey Peptides Blend Calculator engine (_ops/blend/engine.js), run at build time on October 3, 2026 with the presets in _ops/blend_presets.py; hand-checked cases in _ops/blend_test.py.
- FDA. EGRIFTA WR (tesamorelin) prescribing information, section 2: 1.28 mg once daily (via the Grey Peptides tesamorelin entry). Read October 3, 2026.
- Grey Peptides ipamorelin entry and comparison pages: never approved; the 114-patient phase 2 trial after bowel resection found no significant benefit (PMID 25331030). Read October 3, 2026.
- FDA. Wegovy (semaglutide) prescribing information, section 2: 0.25 mg weekly starting dose (via the Grey Peptides semaglutide entry). Read October 3, 2026.
- Grey Peptides cagrilintide entry: trial doses 0.3 to 2.4 mg weekly (PMIDs 34798060 and 40544433). Read October 3, 2026.
- Grey Peptides Blend Calculator example compositions and notes (_ops/blend_presets.py): no blend has been studied as a blend. Read October 3, 2026.
- Ashraf, A. R., et al. (2024). Multifactor Quality and Safety Analysis of Semaglutide Products Sold by Online Sellers Without a Prescription: Market Surveillance, Content Analysis, and Product Purchase Evaluation Study. J Med Internet Res, 26, e65440. PMID: 39509151
- FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Content current as of April 22, 2026; read October 3, 2026. FDA
Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose.
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