What it is
Pentosan polysulfate sodium (PPS) is a semi-synthetic polysaccharide, a large sugar-based molecule. It is FDA-approved, as Elmiron, for interstitial cystitis and is studied for osteoarthritis and joint tissue support. In the U.S., Elmiron is an oral capsule FDA-approved for the relief of bladder pain or discomfort associated with interstitial cystitis, a chronic bladder condition.
The approved product is taken by mouth. The injectable vial form listed in the PeptidesAI encyclopedia is not the FDA-approved product, and the joint uses discussed here are not FDA-approved.
How it's thought to work
Pentosan polysulfate is a heparin-like molecule described as having anti-inflammatory and chondroprotective effects, meaning effects that protect cartilage. It is described as supporting the glycosaminoglycan layer (a protective coating of long sugar chains), modulating cartilage metabolism and improving microcirculation.
The Elmiron prescribing information describes pentosan polysulfate sodium as a low molecular weight, heparin-like compound with anticoagulant and fibrinolytic effects, and states that its mechanism of action in interstitial cystitis is not known.
What the research says
Pentosan polysulfate is FDA-approved as Elmiron for interstitial cystitis. Veterinary and human osteoarthritis research is described as supporting chondroprotective effects.
A randomized, double-blind, placebo-controlled pilot study of 114 people with knee osteoarthritis found differences from the control group in some clinical assessments, including duration of joint stiffness, pain at rest and patient global assessment.
Elmiron is not FDA-approved for joint use.
Reported side effects
Reported side effects include a bleeding and bruising risk due to anticoagulant activity, gastrointestinal upset and hair thinning. The prescribing information describes it as a weak anticoagulant that may increase bleeding times, with alopecia (hair loss), nausea and diarrhea among the reported adverse reactions.
The prescribing information also warns of pigmentary changes in the retina, reported as pigmentary maculopathy, with long-term use.
A retrospective case series of six patients with chronic exposure to pentosan polysulfate sodium described a distinctive pigmentary maculopathy.
Reconstitution
The FDA-approved pentosan polysulfate product, Elmiron, is an oral capsule and is not reconstituted. This page instead covers the 100 mg vial for injection listed in the PeptidesAI encyclopedia, where the amount of diluent varies, so the worked example below only illustrates the arithmetic.
Worked example. A 100 mg vial is 100,000 mcg. Reconstituted with 2 mL of BAC water, that works out to 100,000 mcg ÷ 2 mL = 50,000 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 50,000 × 0.01 = 500 mcg. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
Pentosan polysulfate has anticoagulant activity, which is a significant bleeding-risk consideration. Retinal maculopathy has been linked to long-term oral use. It is not FDA-approved for joint use.
Sources
- ELMIRON (pentosan polysulfate sodium) capsules - Prescribing Information. U.S. Food and Drug Administration, 2021. Fda label
- Pigmentary Maculopathy Associated with Chronic Exposure to Pentosan Polysulfate Sodium. Pearce WA et al. Ophthalmology, 2018. Human trial
- Effects of pentosan polysulfate in osteoarthritis of the knee: A randomized, double-blind, placebo-controlled pilot study. Ghosh P et al. Current Therapeutic Research, 2005. Human trial
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is pentosan polysulfate?
A semi-synthetic, heparin-like polysaccharide, FDA-approved as the oral capsule Elmiron for interstitial cystitis and studied for osteoarthritis and joint tissue support.
How is pentosan polysulfate thought to work?
It is a heparin-like molecule described as having anti-inflammatory and chondroprotective effects; the Elmiron label says its mechanism in interstitial cystitis is not known.
What does the research on pentosan polysulfate say?
It is FDA-approved for interstitial cystitis, and a small randomized pilot study in knee osteoarthritis found differences from placebo in some clinical assessments.
What are the reported side effects of pentosan polysulfate?
Bleeding and bruising risk from its weak anticoagulant activity, gastrointestinal upset, hair loss, and a retinal pigmentary maculopathy linked to long-term use.
How much is one unit from a 100 mg Pentosan Polysulfate vial?
With 2 mL of BAC water, a 100 mg vial is 50,000 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 500 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for Pentosan Polysulfate — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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