Best Prostamax vendors in 2026
Buying Prostamax: what the field looks like
We track 6 in-stock Prostamax listings across 6 US retail vendors, and re-read every one of them each night. Ranking below is by cost per milligram, which is the only figure that compares a 5mg vial against a 10mg one honestly.
The cheapest source works out at $2.00/mg against a median of $2.95/mg across the field — 32% less for the same milligram of the same compound. That gap is why this page exists: on Prostamax the vendor you pick matters more than the size you buy.
The lowest total cart is $39.99 at erospeptides. That is the cheapest way to hold Prostamax at all, which is a different question from the best cost per milligram — the two are the same vendor only sometimes.
Top 5 Prostamax vendors at a glance
| # | Vendor | Size | Cheapest vial | Per mg | vs median | Score | |
|---|---|---|---|---|---|---|---|
| 1 | erospeptides | 20mg | $39.99 | $2.00 | 32% under | 7.8/10 | View → |
| 2 | peptidecrafters | 25mg | $55.00 | $2.20 | 25% under | 7.6/10 | View → |
| 3 | libertypeptides | 20mg | $55.00 | $2.75 | 7% under | 5.2/10 | View → |
| 4 | corepeptides | 20mg | $63.00 | $3.15 | — | 4.5/10 | View → |
| 5 | aiopeptides | 20mg | $64.00 | $3.20 | — | 5.5/10 | View → |
All 6 ranked Prostamax vendors
erospeptides
20mg$39.99$2.00/mg7.8/10Get deal →Prices sit in the 31th percentile of each compound's field — cheaper than 69% of listings. · Cheapest source we track on 7 compounds. · 52 compounds, 80 live listings. · 95% of listings in stock at the last check. · Certificates published on 60% of listings, newest 2 months old. · Tracked for 2 days.
peptidecrafters
25mg$55.00$2.20/mg7.6/10Get deal →Prices sit in the 34th percentile of each compound's field — cheaper than 66% of listings. · 33 compounds, 34 live listings. · 87% of listings in stock at the last check. · Certificates published on 100% of listings, newest 1 months old. · Tracked for 2 days.
libertypeptides
20mg$55.00$2.75/mg5.2/10Get deal →Prices sit in the 54th percentile of each compound's field — cheaper than 46% of listings. · Cheapest source we track on 4 compounds. · 37 compounds, 42 live listings. · 97% of listings in stock at the last check. · No certificates published that we could find. · Tracked for 2 days.
corepeptides
20mg$63.00$3.15/mg4.5/10Get deal →Prices sit in the 68th percentile of each compound's field — cheaper than 32% of listings. · 34 compounds, 40 live listings. · 96% of listings in stock at the last check. · No certificates published that we could find. · Tracked for 2 days.
aiopeptides
20mg$64.00$3.20/mg5.5/10Get deal →Prices sit in the 49th percentile of each compound's field — cheaper than 51% of listings. · 36 compounds, 38 live listings. · 100% of listings in stock at the last check. · Certificates published on 3% of listings, newest 8 months old. · Tracked for 2 days.
biolongevitylabs
20mg$79.97$4.00/mg5.4/10Get deal →Prices sit in the 78th percentile of each compound's field — cheaper than 22% of listings. · Cheapest source we track on 1 compound. · 33 compounds, 36 live listings. · 89% of listings in stock at the last check. · Certificates published on 100% of listings, newest 18 months old. · Tracked for 2 days.
Prostamax vial sizes compared
Vendors sell Prostamax in 2 sizes. Cost per milligram is not the same across them, so the biggest vial is not automatically the best value.
| Vial size | Vendors | Cheapest | Best per mg | At |
|---|---|---|---|---|
| 20mg | 5 | $39.99 | $2.00 | erospeptides |
| 25mg | 1 | $55.00 | $2.20 | peptidecrafters |
Prostamax price history
Median cost per milligram across the field, one point per day we crawled.
How we rank these vendors
Vendors are ordered by cost per milligram of their cheapest in-stock single vial. Nothing else moves the order — not commission, not whether a vendor has a partner programme, not how long we have tracked them.
The score beside each vendor is a listing-quality score, not a purity or trust score. We have no laboratory and we do not test anything. It is built from figures we measure ourselves: where the vendor's prices sit inside each compound's own field, how many compounds they carry, how reliably their listings stay in stock, and how many certificates they publish. Every input is shown beside the number.
Prices older than 48 hours are dropped rather than shown stale, so a vendor missing from this page is usually a vendor whose site we could not read last night.
Common questions
Who sells Prostamax cheapest right now?
erospeptides, at $2.00 per milligram and $39.99 for the cheapest single vial. That is across 6 US retail vendors, checked within the last 24 hours.
How much should Prostamax cost per mg?
The median across 6 vendors is $2.95/mg. Anything at or under that is a fair price; the cheapest we can find is $2.00/mg, and the top of the market runs to $3.80/mg.
Which vial size of Prostamax is the best value?
Vendors sell Prostamax in 2 different vial sizes, and the cost per milligram is not the same across them. The table above prices each size separately so you can see which one is actually cheaper per mg rather than per vial.
Do you sell Prostamax?
No. We sell nothing and ship nothing. Every link goes to the vendor's own store, and some of them pay us a commission — those are labelled on the row, and commission never affects the ranking, which sorts on price alone.