Antifibrotic (pyridone)

Esbriet (pirfenidone)

An approved treatment for Idiopathic Pulmonary Fibrosis.

FDA Approved (2014)by Legacy Pharma (Esbriet brand, acquired from Genentech in 2025); generic versions from several makers

Preclinical

Phase 1

Phase 2

Phase 3

Approved

2014

Drug facts

The same compound appears under different names depending on the context. Here is how to identify Pirfenidone wherever you encounter it, plus the key facts at a glance.

Generic name: Pirfenidone
Brand name: Esbriet
Drug class: Antifibrotic (pyridone)
Manufacturer: Legacy Pharma (Esbriet brand, acquired from Genentech in 2025); generic versions from several makers
How it's taken: 801 mg by mouth 3 times a day with food, a total of 2,403 mg a day.

One of the first 2 drugs approved for idiopathic pulmonary fibrosis, in October 2014. It is taken 3 times a day with food and slowed the loss of lung capacity in its main trial. Generic versions have been approved since 2022, and the Esbriet brand moved from Genentech to Legacy Pharma in November 2025.

Where Pirfenidone fits

One of the 2 original IPF drugs from 2014, alongside nintedanib. Nerandomilast (Jascayd), approved in October 2025, can be added to it at the full 18 mg dose.

How Pirfenidone works

Pirfenidone's label states that exactly how it works in IPF has not been established. In people with IPF it slows the loss of lung capacity. It does not reverse scarring that has already formed.

Mechanism: Oral antifibrotic of the pyridone class whose exact mechanism in IPF has not been established

Side effects and safety

What patients report

Label warnings

Liver injury. Liver enzyme and bilirubin rises can happen, rarely severe or fatal. Blood tests before starting, monthly for 6 months, then every 3 months.
Sun sensitivity and rash. Avoid sunlight and sunlamps, and wear sunscreen and protective clothing every day.
Severe skin reactions. Rare cases of Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS; stop and call your doctor if a severe rash or blistering appears.
Stomach and bowel side effects. Nausea, indigestion, diarrhea and vomiting are common and may need a lower or paused dose.

Most common in trials

Nausea (36% against 16% on placebo)Rash (30% against 10%)Upper respiratory infection (27% against 25%)Diarrhea (26% against 20%)Fatigue (26% against 19%)Abdominal pain (24% against 15%)Decreased appetite (21% against 8%)

What gets monitored

Liver tests before starting, monthly for the first 6 months, then every 3 months

Report a suspected reaction to Legacy Pharma at 1-800-727-7151 or FDA MedWatch at 1-800-FDA-1088, or to the FDA at 1-800-FDA-1088.

In context

The most common side effects in the IPF trials, against placebo, were nausea (36% against 16%), rash (30% against 10%), upper respiratory infection (27% against 25%), diarrhea (26% against 20%), fatigue (26% against 19%), abdominal pain (24% against 15%) and decreased appetite (21% against 8%). The label warns about liver injury, including rare fatal cases, and calls for liver blood tests before starting, monthly for the first 6 months and every 3 months after that. It makes skin more sensitive to the sun, so the label advises daily sunscreen and protective clothing and avoiding sunlamps. Rare severe skin reactions such as Stevens-Johnson syndrome have been reported^[1].

This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.

Taking Pirfenidone

801 mg by mouth 3 times a day with food, a total of 2,403 mg a day. The dose builds up over 14 days, 267 mg 3 times a day for the first week and 534 mg 3 times a day for the second. If 14 or more days are missed, the build-up starts again. Lower doses are used with strong CYP1A2 inhibitors such as fluvoxamine, and smoking lowers pirfenidone levels^[1].

Availability and cost

Generic available

Generic versions may be available at a lower cost. Ask your pharmacist.

Help paying for Esbriet

Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.

Your insurance

From the drugmaker

Esbriet (Pirfenidone)

Esbriet Co-pay Program and Legacy Patient Program (Legacy Pharma)

Official program page Call 1-866-435-8080

Copay help
Esbriet Co-pay Program: eligible patients with commercial insurance may pay as little as $5 per 30-day supply of Esbriet, with up to $25,000 in assistance per calendar year. Not for state or federal health plans.
For: private insurance · source
Free medicine program
Legacy Patient Program: free Esbriet for eligible patients who are uninsured, whose insurance does not cover Esbriet, or whose out-of-pocket costs are high, with household income under $150,000 for 1 to 4 people. Call 1-866-435-8080.
For: no insurance, underinsured · source

Good to know: Legacy Pharma took over US sales of Esbriet from Genentech on November 3, 2025, so Genentech's programs no longer cover it. Generic pirfenidone has been available since 2022.

Checked on the drugmaker's official pages on September 29, 2026. Programs change; confirm with the program before you rely on it.

Charity funds for Idiopathic Pulmonary Fibrosis

From a charity · The Assistance Fund
Idiopathic Pulmonary Fibrosis fund
Waitlist
Apply on the foundation’s page
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”

Status as each foundation showed it on September 28, 2026.

More ways to get help paying for treatment →

Clinical trial results

In the ASCEND trial (NCT01366209) of 555 adults with IPF, forced vital capacity fell 235 mL over 52 weeks on pirfenidone against 428 mL on placebo, a difference of 193 mL^[1]^[2]. In the earlier CAPACITY program, one of 2 trials showed a 157 mL benefit at 72 weeks and the other did not reach statistical significance^[1].

Development history

The FDA approved pirfenidone capsules as Esbriet on October 15, 2014, the same day as nintedanib, making them the first 2 drugs for IPF, and film-coated tablets followed in January 2017. Genentech, part of Roche, sold Esbriet in the US until Legacy Pharma acquired the US rights in 2025 and took over supply and sales on November 3, 2025^[3]. The FDA approved the first generic pirfenidone versions in January 2022^[4].

Ask anything about Pirfenidone

AI-powered answers from clinical trial databases, FDA reports, and medical literature

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Explore Idiopathic Pulmonary Fibrosis trials

Other Idiopathic Pulmonary Fibrosis treatments

IPF has 3 approved antifibrotic drugs, pirfenidone, nintedanib and nerandomilast (Jascayd, approved October 2025). All 3 slow the decline in lung function.

Common questions about Pirfenidone

▸What is Pirfenidone (Esbriet)?

▸How does Pirfenidone work?

Pirfenidone's label states that exactly how it works in IPF has not been established. In people with IPF it slows the loss of lung capacity. It does not reverse scarring that has already formed.

▸What are the side effects of Pirfenidone?

▸How is Pirfenidone taken?

▸Is Pirfenidone FDA approved?

Yes, Pirfenidone (Esbriet) is FDA approved (2014) for the treatment of Idiopathic Pulmonary Fibrosis.

▸Is there a generic version of Esbriet?

Yes. The FDA approved the first generic pirfenidone versions in January 2022, and several companies make them in tablet and capsule forms. Ask your pharmacist or insurer which version your plan covers.

▸Who makes Esbriet now?

Legacy Pharma took over US supply, distribution and sales of Esbriet from Genentech on November 3, 2025. Legacy Pharma answers clinical questions at 1-866-930-0188 and takes side effect reports at 1-800-727-7151.

▸Why do I need sunscreen on pirfenidone?

Pirfenidone makes skin more sensitive to sunlight. In the trials, rash occurred in 30% of patients against 10% on placebo and photosensitivity reactions in 9% against 1%. The label advises avoiding sun and sunlamps and wearing sunscreen and protective clothing every day.

Sources and references

Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.

U.S. National Library of Medicine, DailyMed. ESBRIET (pirfenidone) capsules and tablets, for oral use: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2e8c3537-36d7-4de5-9b5c-7a624b9a9e6e
New England Journal of Medicine · 2014. A Phase 3 Trial of Pirfenidone in Patients with Idiopathic Pulmonary Fibrosis. https://www.nejm.org/doi/full/10.1056/NEJMoa1402582
Genentech. Esbriet (pirfenidone): transfer of US rights to Legacy Pharma. https://www.gene.com/patients/medicines/esbriet
U.S. Food and Drug Administration. 2022 First Generic Drug Approvals. https://www.fda.gov/drugs/drug-and-biologic-approval-and-ind-activity-reports/2022-first-generic-drug-approvals
Legacy Pharma. Esbriet assistance options. https://www.esbriet.com/assistance-options.html