Is desirudin FDA-approved, and what does the research show?

What is desirudin?

Desirudin is an anticoagulant, a drug that slows blood clotting, of the kind often called a blood thinner ², ³. It was sold as Iprivask, a powder dissolved and then injected under the skin ². Its label gave it one job, around a planned hip replacement: "the prophylaxis of deep vein thrombosis, which may lead to pulmonary embolism" ². Prophylaxis means prevention. Deep vein thrombosis, or DVT, is a type of blood clot, and a pulmonary embolism is a blood clot in the lungs ³.

Desirudin is not a wellness, weight-loss or performance peptide, and its label named no such use ². It was a surgical drug, started shortly before the operation ².

The molecule is modeled on hirudin, which the label called "the naturally occurring anticoagulant" in the glands of the medicinal leech ². Hirudin is a single chain of 65 amino acids, the building blocks of proteins ². Desirudin was made by recombinant DNA technology, in yeast cells given the gene for the protein, hence its other name, recombinant hirudin ², ⁵. It differs from the leech's hirudin by lacking one sulfate group, a small chemical attachment of sulfur and oxygen ².

Is desirudin FDA-approved?

FDA approved desirudin in 2003; Drugs@FDA now lists the product as "Discontinued" ¹, and FDA's Purple Book lists its license as "Voluntarily Revoked" ⁴. FDA approved desirudin, as Iprivask, on April 4, 2003 ¹. Drugs@FDA, FDA's database of approved drugs, lists it under biologics license application (BLA) 021271, with Bausch as the sponsor ¹. A BLA is the application FDA uses for a biological product. The Purple Book is FDA's "Database of Licensed Biological Products" ⁴.

Drugs@FDA lists the one Iprivask product in its record with marketing status "Discontinued" as of November 9, 2026, the date of the record's data ¹. The Purple Book's October 2026 data list the same product with licensure "Voluntarily Revoked" ⁴. Neither record gives a date or a reason for the discontinuation or the revocation ¹, ⁴.

While Iprivask was sold, its label gave one indication, limited to "patients undergoing elective hip replacement surgery" ². Elective surgery is planned surgery. The label quoted here is the November 2014 revision, the latest in the Drugs@FDA record ¹, ².

See the FDA status of every peptide, updated weekly.

How does desirudin work?

The 2014 label's account rested on clotting tests of human plasma and on studies in volunteers and patients ². It called desirudin "a direct inhibitor of free circulating and clot-bound thrombin" ². Thrombin is a clotting enzyme in the blood, and a direct inhibitor attaches to the enzyme itself ². "One molecule of desirudin binds to one molecule of thrombin and thereby blocks the thrombogenic activity of thrombin," the label said ². Thrombogenic means clot-forming, and the pair forms "an extremely tight, non-covalent complex," one held without a permanent chemical bond ².

At treatment levels, the label said, desirudin had no effect on the other clotting enzymes it listed, or on digestive enzymes such as trypsin ². Its effect showed on a blood test, the activated partial thromboplastin time (aPTT), which measures how long plasma takes to clot ². The aPTT rose as the dose rose ².

After an injection under the skin, blood levels peaked between 1 and 3 hours ². The half-life, the time the body takes to clear half of the drug, was about 2 hours ². The kidneys did most of the clearing, and 40 to 50 percent of a dose left in the urine unchanged ². In people with severe kidney impairment, the half-life stretched to as long as 12 hours ².

What does the research show?

Studied in people: the label described "two controlled, randomized, multicenter, clinical efficacy trials" in patients having a total hip replacement ². Randomized means chance decided which drug each patient received, and multicenter means several hospitals took part. Each trial compared desirudin with another injected anticoagulant, heparin in one and enoxaparin in the other ². In both, treatment began before surgery and continued for 8 to 12 days afterward ².

A paper published in March 1997 reports a trial against heparin whose patient numbers match the label's first trial; the label names no publication ⁵, ². The paper's trial was double-blind: neither patients nor doctors knew which drug a patient received ⁵. It randomized 445 patients having a first, planned total hip replacement, 225 to desirudin and 220 to heparin ⁵. Both drugs were injected under the skin, desirudin twice a day and heparin three times a day ⁵. Clots were sought with venograms, images of the veins of both legs, read by two independent radiologists ⁵.

The paper's per-protocol analysis covered the 351 patients who had an adequate venogram or a proven clot ⁵. Among them, DVT was confirmed in 13 of 174 given desirudin (7 percent) and 41 of 177 given heparin (23 percent) ⁵. The paper reports the difference as significant, meaning unlikely to be chance (p < 0.0001) ⁵. Counting every randomized patient, the label gave venous thromboembolic events (VTE) in 13 of 225 on desirudin (5.8 percent) and 42 of 220 on heparin (19.1 percent) ². VTE, in the label's count, meant DVT, pulmonary embolism, or a death judged to come from a clot ².

No pulmonary embolism or death was confirmed during treatment ⁵. In the six weeks of follow-up, pulmonary embolism was confirmed in four patients, all of whom had received heparin ⁵. The paper found no significant difference between the groups in bleeding ⁵.

The label's second trial compared desirudin with enoxaparin in 2,079 randomized patients, 1,043 assigned to desirudin and 1,036 to enoxaparin ². Counting every randomized patient, VTE occurred in 145 on desirudin (13.9 percent) and 199 on enoxaparin (19.2 percent), with p = 0.001 ². Major events, which the label defined as "proximal DVT, PE, or death," occurred in 39 (3.7 percent) and 61 (5.9 percent), with p = 0.024 ². Proximal means the part of the leg nearer the body, and PE is pulmonary embolism.

The mean age in both trials was about 68, and the label stated that all enrolled patients were Caucasian ². In a separate dose-finding study, the label reported that effectiveness and bleeding both rose with the dose ². In a smaller open-label study, where everyone knew what was given, the highest dose "was associated with unacceptable major bleeding" ².

Every efficacy and dose-finding study the label described was in hip replacement surgery ². The label reported no data on body weight or athletic performance ². It said safety and effectiveness in children "have not been established" ².

What are the side effects?

Bleeding was the most common adverse reaction on the label ². Across the label's hip replacement studies, hemorrhage of any kind was recorded in 464 of 1,561 patients given desirudin at the label's regimen (30 percent) ². The figures for the comparison drugs were 111 of 501 given heparin (22 percent) and 341 of 1,036 given enoxaparin (33 percent) ². Serious hemorrhage, defined by blood loss or transfusion need, was recorded in 3 percent, 3 percent and 2 percent ². Major hemorrhage was recorded in 13 patients on desirudin and 2 on enoxaparin, under 1 percent of each group, and in none on heparin ².

The label's Highlights, its summary page, listed other reactions seen in at least 2 percent of patients: "injection site mass, wound secretion, anemia, deep thrombophlebitis and nausea" ². In the label's table, each was recorded in 2 to 4 percent of desirudin patients; on heparin, the table's DVT row reached 8 percent ². Deep thrombophlebitis is inflammation of a deep vein with a clot.

Allergic events were reported in fewer than 2 percent of desirudin patients in the late-stage (phase 3) trials ². After approval, the label recorded reports of major hemorrhages, "some of which were fatal," and of anaphylactic reactions, which are severe allergic reactions ². It noted that these reports came from "a population of unknown size," so their frequency is not known ².

The label opened with a boxed warning, a warning set in a box at its head, about anesthesia given near the spine ². The warning covered epidural or spinal anesthesia and spinal puncture in patients given thrombin inhibitors such as Iprivask ². Such patients, it said, "may be at risk of developing an epidural or spinal hematoma which can result in long-term or permanent paralysis" ². Drugs.com, a consumer drug reference, describes this as a blood clot around the spinal cord ³.

The label marked desirudin as "contraindicated," not to be used, in two groups ². The first was "patients with known hypersensitivity to natural or recombinant hirudins due to risk of anaphylaxis" ². The second was "patients with active bleeding and/or irreversible coagulation disorders due to risk of hemorrhage" ². One statement is Drugs.com's, not the label's: the page named allergy to "Iprivask, bivalirudin, or lepirudin," the last two being other medicines, as a reason not to use it ³.

The label called for caution in kidney impairment "due to an increased risk for bleeding," with a reduced dose and daily blood tests ². It told prescribers to avoid "use with other drugs that inhibit or modify platelet function or affect blood clotting" ². Its examples included other anticoagulants and NSAIDs, nonsteroidal anti-inflammatory drugs, a class of painkillers ². It stated that no "specific antidote for Iprivask is available" ².

The label said there were "no adequate and well controlled studies in pregnant women," and that the drug caused birth defects in rats and rabbits ². Serious adverse events "occurred more frequently in patients 75 years of age or older" than in those under 65 ². The label also said Iprivask "cannot be used interchangeably with other hirudins," which differ in how they are made and in their activity ².

In sport

WADA, the World Anti-Doping Agency, does not name desirudin on its 2026 Prohibited List ⁶. The list does not name hirudins, thrombin inhibitors or anticoagulants as a class either ⁶.

Section S0 of the list reads: "Any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use (e.g. drugs under pre-clinical or clinical development or discontinued, designer drugs, substances approved only for veterinary use) is prohibited at all times" ⁶. FDA is the only regulator whose records are cited here, and its Purple Book lists the license as "Voluntarily Revoked" ⁴.

What JumpstartMD offers

JumpstartMD does not prescribe desirudin. Our peptide library covers it so you have the facts on its FDA status and the evidence, current as of November 10, 2026.

Ready to talk?

Book FREE Consultation

Share your details and a JumpstartMD team member will reach out shortly. Or call 408.478.3496 for your free, no-obligation consultation.

Share your details and a JumpstartMD team member will reach out when we open.

Disclaimer

Compounded medications are not FDA-approved, and FDA does not review their safety, effectiveness, or quality before they are marketed. A licensed clinician decides after an evaluation whether a peptide is appropriate for you, and not every patient will qualify.