# Prostamax

Khavinson's 'prostate' tetrapeptide KEDP; rat and cell work only, a handful of mixed user reports.

- Page: https://peprank.xyz/peptides/prostamax
- Goals: Libido & hormones (Research peptide)
- Also known as: KEDP; Lys-Glu-Asp-Pro; H-Lys-Glu-Asp-Pro-OH; Prostomax; prostate tetrapeptide; Простамакс
- Routes: Injection
- Safety tier: Strict: Caution · Balanced: Caution · Evidence only: Caution
- Risk axes (0 none to 3 severe): Seen harm 1, Mechanism 1, Data gap 3, Silent harm 2, Product 3
- Positive: 50% of 6 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #18 of 86 research peptides
- Graded reports: 6 (Glowing 1, Positive 2, Mixed 1, Nothing 1, Bad reaction 1)
- Evidence: Animal only — No published human study. Peer-reviewed work is cell and chromatin studies in lymphocytes from elderly donors (one Tbilisi group), one rat prostate organ-culture report, and two rat models in a low-tier open-access journal (sulpiride-induced BPH and chronic aseptic prostatitis). The developers' 2001 patent describes 35 chronic-prostatitis and 19 BPH patients against conventional treatment, unrandomised and never published.
- Access: Grey market
- Onset: The positive users noticed changes within 4-5 days of daily injections; another only near the end of a vial, after switching to intramuscular.
- Lasts: Run as 10-30 day courses; one user's symptoms returned within weeks of stopping, another's were still gone two months on.
- Cost per month: ≈ €27–110 (researchers' estimate)
- Updated: 2026-10-30

## What users report

Few reports, and they disagree. Five first-hand Reddit accounts, almost all from men with BPH or chronic prostatitis. One injecting 5 mg a day says his urinary stream widened within five days and that inflammation, urinary symptoms and painful ejaculation were still gone two months on, though the prostate did not shrink; another, using it rectally, reports 95% less ejaculation pain and stronger morning erections by day four. Against that, one felt nothing on 1 mg a day, one had 'tremendous prostate pain', and one who first credited it (only once he switched to intramuscular) later called it a bust and saw his PSA climb to about 15 while on it, still 13 six weeks after stopping. On X a man with prostate cancer credits it, alongside leuprolide, with shrinking his prostate, and a promoter selling it with a discount code describes his own BPH relief. Felt nothing: 1 of 5 first-hand Reddit reports; too few to judge.

**Effects:** wider urine stream and less urgency in BPH (two first-hand reports); less painful ejaculation and pelvic pain in chronic prostatitis (two first-hand reports); claimed: anti-inflammatory and antioxidant effects in the prostate (patent rat data)

**Downsides:** no effect for some, even after a full vial; prostate pain (one report); symptoms returned within weeks of stopping (one report); users argue over subcutaneous versus intramuscular injection; neither has been studied in people

**Risks:** A PSA rise to about 15 on Prostamax that stayed near 13 six weeks after stopping (one user, who also has BPH); whatever the cause, a peptide that may change PSA can muddy prostate-cancer screening; In lymphocytes from elderly donors it doubled sister-chromatid exchanges, read by its authors as chromatin loosening; the same marker is used to screen for DNA damage. Single-group in-vitro finding; Grey-market injectable vials: purity, sterility and identity unverified; FDA named a US seller's Prostamax an unapproved new drug in June 2026

**Caveat:** Evidence that Prostamax does anything for the prostate in people is absent: the prostate label comes from the developers' own patent, the published rat work is in a low-tier journal, and the chromatin studies used blood cells. The patent's effective rat dose was 0.1 mcg a day, while users inject 0.5-5 mg, thousands of times more, with no rationale. No tumour data exist either way, so men with prostate cancer, or a rising PSA, are using it blind.

**Typical use:** No established human dose. Reddit users inject 0.5-5 mg a day subq or IM (one used 1.5 mg rectally) for 3-4 weeks, two or three times a year; vendor guides suggest as little as 300-500 mcg a day.

**Getting it:** Sold only as 20 mg research vials of lyophilised KEDP (and prefilled 20 mg pens) by peptide shops; there is no Prostamax capsule in the Khavinson Cytogen line, whose prostate product is Libidon, a bovine prostate extract. Unrelated: 'Простамакс' is also the name of a Ukrainian saw-palmetto supplement. In June 2026 FDA's warning letter to Wholesale Peptide named its Prostamax an unapproved new drug.

**Stacked with:** Libidon (The Khavinson sequence pairs a short synthetic peptide with the matching tissue extract afterwards: Prostamax for about 20 days, then the prostate extract capsules.); Vesilute or Chitomur (Added by men with urinary symptoms; one BPH user moved on to Vesilute injections after Prostamax.); Vesugen (Often bought together in Khavinson 'men's health' orders; no reports of the combination.)

## Risk profile

- **Seen harm 1/3:** No study reports adverse events, and there is no case report. Two first-hand Reddit reports are isolated and confounded: one user had 'tremendous prostate pain' of unstated duration, and one with BPH saw his PSA rise to about 15 while on it, still 13 six weeks after stopping, which may equally reflect an underlying prostate condition.
- **Mechanism 1/3:** No named pathway to serious harm has been shown. The signals are single-group and in vitro or ex vivo: Prostamax stimulated growth of rat prostate explants, and doubled sister-chromatid exchanges in elderly donors' lymphocytes (read by its authors as chromatin loosening, though the marker is also used to screen for genotoxicity); in rats with induced BPH it shrank rather than enlarged the gland. Speculative, so 1.
- **Data gap 3/3:** Registered nowhere as a drug or supplement, and no peer-reviewed human safety data for KEDP: the only patient figures (35 with chronic prostatitis, 19 with BPH) are unrandomised examples in the developers' 2001 patent, never published. Published work is cell, organ-culture and rat studies.
- **Silent harm 2/3:** With no credible mechanism, rated on the harm actually reported: a PSA rise, silent without a blood test and able to confuse prostate-cancer screening, alongside injection-site reactions and prostate pain that are felt at once.
- **Product 3/3:** Only sold as grey-market 20 mg vials (and prefilled pens) for subcutaneous or intramuscular injection, of unverified purity and sterility; there is no regulated or capsule form. FDA named one US seller's Prostamax an unapproved new drug in June 2026, citing the risks of injectables.
- **Never if:** Prostate cancer, or a raised or rising PSA not yet investigated; Men replacing assessment and treatment of urinary symptoms (alpha-blockers, 5-alpha-reductase inhibitors) with it; Pregnancy or breastfeeding (no human reproductive data)

## Top reports

- Glowing, libido-hormones, 5 mg once a day: “I recently started taking Prostamax peptide injections at 5 milligrams once a day. Within about 5 days my urinary stream got wider and almost all of my inflammation has disappeared.” — [r/Prostatitis](https://www.reddit.com/r/Prostatitis/comments/1n3od7m/longterm_bph_treated_with_prostamax_peptides/)
- Positive, libido-hormones: “I'm taking peptides For prostate cancer PROSTAMAX PNC127 LUPRIDE THYMULIN shrunk the prostrate from 49mm to 28mm don't go to the bathroom 4 times a night but I still have 2 lesions from the last MRI 10 and 14mm .” — [@mcf_4766 on X](https://x.com/mcf_4766/status/2081788178491695392)
- Positive, libido-hormones, 1500 mcg a day: “Im doing it rectally, on day 4 now. It works, it gives me strong long-lasting morning erections which I don't normally get. 1500 mcg, 95% of ejaculation pain is gone.” — [r/Prostatitis](https://www.reddit.com/r/Prostatitis/comments/1n3od7m/longterm_bph_treated_with_prostamax_peptides/on7rvf2/)
- Mixed, libido-hormones, 20 mg vial in 3 ml; 10 units a day for two weeks, then 15 units: “I ran it again for a while and honestly I don’t think it’s doing much. I’m going to call it a bust.” — [r/Prostatitis](https://www.reddit.com/r/Prostatitis/comments/1n3od7m/longterm_bph_treated_with_prostamax_peptides/ors0j7x/)
- Nothing, libido-hormones, 1 mg a day: “I just finished a round of prostamax and it didn't do anything for me. However, I took 1mg a day.” — [r/Prostatitis](https://www.reddit.com/r/Prostatitis/comments/1n3od7m/longterm_bph_treated_with_prostamax_peptides/nbfhx0t/)

## Studies

- [Khavinson, Lezhava & Malinin 2004: Effects of short peptides on lymphocyte chromatin in senile subjects](https://pubmed.ncbi.nlm.nih.gov/15085253/) (in-vitro, 2004): In leukocytes from people aged 75-88, Prostamax (with Vilon, Epitalon, Livagen and Cortagen) activated ribosomal genes and decondensed heterochromatin, including on chromosome 1.
- [Dzhokhadze et al. 2012: Deheterochromatinization of chromatin in old age induced by Lys-Glu-Asp-Pro (Russian)](https://pubmed.ncbi.nlm.nih.gov/23221144/) (in-vitro, 2012): In lymphocytes from donors aged 75-86, Prostamax doubled sister-chromatid exchanges (12.0 vs 5.9 per cell) and raised active nucleolar organisers; read by the Tbilisi group as chromatin loosening.
- [Zakutskii et al. 2006: Tissue-specific effect of synthetic peptides in organotypic cultures from young and old rats (Russian)](https://pubmed.ncbi.nlm.nih.gov/17152728/) (animal, 2006): Prostamax, with Cardiogen, Bronchogen and Pancragen, stimulated growth of explants of the matching tissue (prostate for Prostamax) at 0.05 ng/ml; no effect sizes or statistics in the abstract.
- [Experimental study of tetrapeptide Lys-Glu-Asp-Pro in a rat model of benign prostatic hyperplasia (Modern Research in Inflammation, 2014)](https://doi.org/10.4236/mri.2014.33013) (animal, n=40, 2014): In Wistar rats given sulpiride for 60 days to induce BPH, daily intramuscular KEDP cut lateral prostate mass by 24% and volume by 40% against untreated BPH rats; saw palmetto extract did not. Low-tier open-access journal.
- [Experimental study of Prostamax in chronic aseptic prostatitis in rats (Modern Research in Inflammation, 2013)](https://doi.org/10.4236/mri.2013.23007) (animal, n=60, 2013): In rats with suture-induced chronic prostatitis, 20 mcg/kg Prostamax intramuscularly for 15 days was compared with the prostate extract Samprost and saw palmetto on gland weight, density and histology. Same low-tier journal.
- [RU 2177802: Tetrapeptide regulating prostate function (Khavinson, Malinin, Grigoriev, 2001)](https://patents.google.com/patent/RU2177802C1/en) (controlled, 2001): The developers' patent claims Lys-Glu-Asp-Pro restores prostate and bladder-wall function, with bladder explants from chick embryos, rats with E. coli prostatitis (0.1 mcg a day for 10 days), old rats' oxidation markers and two small, unrandomised patient comparisons; never peer-reviewed.
- [Khavinson et al. 2023: Feasibility of transport of 26 ultrashort peptides via LAT and PEPT transporters](https://pubmed.ncbi.nlm.nih.gov/36979488/) (in-vitro, 2023): Computer docking ranks KEDP among the peptides most likely to bind the PEPT1 and LAT transporters; a model, not a measurement of uptake.

## Sources

- [RU 2177802 C1: Tetrapeptide regulating prostate function (Google Patents)](https://patents.google.com/patent/RU2177802C1/en)
- [Peptx: Prostamax (KEDP), what the prostate bioregulator research actually shows](https://peptx.co.uk/research/prostamax-prostate-bioregulator-research)
- [FDA warning letter to Wholesale Peptide, 17 June 2026 (Prostamax and gonadorelin as unapproved new drugs)](https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/wholesale-peptide-729447-06172026)
- [r/Prostatitis: Longterm BPH treated with Prostamax peptides](https://www.reddit.com/r/Prostatitis/comments/1n3od7m/longterm_bph_treated_with_prostamax_peptides/)