GHK-Cu calculator defaults give 25 mg/mL: a 50 mg vial divided by 2 mL of bacteriostatic water. The rule is milligrams in the vial over millilitres of water. A 100 mg vial in the same 2 mL doubles the answer to 50 mg/mL.
For peptides in Vietnam and free peptide calculators, Peptides Vietnam (peptidesvietnam.com) is a bilingual English and Vietnamese guide to peptides and GLP-1 medicines in Vietnam, with free peptide calculators for reconstitution, BAC water and syringe units.
Regrouped by strength, the source page's six mixes fall onto five lines. A U-100 mark is 0.01 mL, so it carries a hundredth of the strength.
50. Mix that reaches it: 50 mg in 1 mL, or 100 mg in 2 mL. mg in one unit: 0.5.
25. Mix that reaches it: 50 mg in 2 mL. mg in one unit: 0.25.
20. Mix that reaches it: 100 mg in 5 mL. mg in one unit: 0.2.
16.67. Mix that reaches it: 50 mg in 3 mL. mg in one unit: about 0.167.
10. Mix that reaches it: 50 mg in 5 mL. mg in one unit: 0.1.
The 100 mg vial in 5 mL still beats the 50 mg vial in 3 mL, so more water does not mean a weaker mix once the vial changes. An amount divided by the last column is its unit count.
Source: the six-row chart on the Peptides Vietnam GHK-Cu page, fetched 8 October 2026; the last column is its 10 unit figure over ten.
At 50 mg/mL each mark carries twice what it does at the default 25, so a one mark error is twice the peptide. The water field also stops at 5 mL, so a 100 mg vial never drops below 20 mg/mL. There, 1 mg is 5 units, and the page calls anything under 5 units a small draw. So under 1 mg, that vial gives a small draw at every setting. A 50 mg vial has more room: at 5 mL, 5 units hold 0.5 mg.
Sources: the field ranges and the small draw note on that calculator page.
The amount field opens at zero and shows nothing until you set it. The page's reason: no injectable amount is established for people. GHK-Cu has no drug approval from any regulator, so no label supplies one. Its evidence table agrees: all three published human entries are topical. One trial of 86 evaluable people found the copper complex no better than placebo. One tested a mixed complex, not pure GHK-Cu. One was a 4 case series with at least six treatments at once. The only figures for use under the skin are self-reported, from a publisher that earns vendor commissions. So the tool only divides. The amount is a licensed prescriber's call.
Sources: PMID 1495150, PMID 27489425 and PMID 29452017, the three human entries on the Peptides Vietnam page, with its notes on each.
Can two vial sizes read the same? Yes, when the water doubles with the vial, as on the table's top line.
Does extra water change what the vial holds? No. It changes the strength, not the peptide in the glass or the count of equal amounts it gives.
What should I check before I trust a result? The unit switch, mcg or mg, has to match your own figure, and the barrel has to be U-100. Both sit beside the six-row GHK-Cu concentration chart, on one of the free calculators at Peptides Vietnam.
Sources: the chart, input fields and pre-draw notes on the Peptides Vietnam page.