Palovarotene
Palovarotene is a retinoid (vitamin A–related) capsule medicine used to reduce new abnormal bone growth in people with fibrodysplasia ossificans progressiva (FOP).
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Palovarotene (Sohonos) is a retinoid (vitamin A-type) medicine for fibrodysplasia ossificans progressiva (FOP). It acts on a receptor called RARγ to turn down the overactive ALK2 bone signal, reducing new bone that forms in muscle and soft tissue, and it has been on the U.S. market since about 2022 as the first medicine approved for FOP. Side effects are common and mostly the dryness retinoids are known for, with dry skin, chapped lips, itching and dry eyes, plus joint pain. Its boxed warning covers serious birth defects, so it is never used in pregnancy, and permanent early closing of growth plates in still-growing children, who need regular growth checks and x-rays.
Clinical pearls
- Take it with food; if swallowing is hard, open the capsule into applesauce, yogurt or oatmeal and take within an hour.
- Avoid grapefruit, pomelo and their juices, and have any new prescription screened, since many drugs raise or lower its levels.
- Avoid tetracycline antibiotics like doxycycline (risk of raised brain pressure) and high-dose vitamin A or other oral retinoids.
- If pregnancy is possible, contraception starts a month before the first dose and continues until a month after the last.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Palovarotene must not be used during pregnancy. It can cause serious birth defects, so it should be given only when pregnancy prevention conditions are met.
In children who are still growing, it can cause the growth plates in bones to close too early, which can affect growth. This is irreversible. Children need close monitoring, including growth checks and x-rays, before and during treatment.
Patient information guide A plain-language walkthrough of Palovarotene, written from its FDA label.
What Palovarotene is used for
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Palovarotene is used for one condition.
- Sohonos (oral capsule) reduces the volume of new heterotopic ossification (bone forming outside the skeleton) in people with fibrodysplasia ossificans progressiva (FOP).
- It is for adults and children aged 8 and older for females and 10 and older for males.
How Palovarotene works
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In FOP, an overactive receptor called ALK2 drives abnormal bone growth in soft tissue. Palovarotene activates a vitamin A–type receptor (RARγ), which dials down the ALK2 signaling pathway. That reduces the cells that form cartilage and bone, so less new bone forms.
Palovarotene dosage
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Sohonos is a capsule taken by mouth once daily with food, preferably at the same time each day.
- Your prescriber sets a daily dose, plus a higher short-term dose during FOP flare-ups. Children's doses are based on weight.
- Capsules can be swallowed whole or opened onto a teaspoon of soft food and taken within 1 hour.
- Avoid grapefruit, pomelo and their juices.
- If you miss a dose, take it as soon as possible. If more than 6 hours have passed, skip it. Never double up or take two doses in one day.
Dosing details from the FDA-approved label
From the Palovarotene prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adults and pediatric patients 14 years and older - daily dose
- 5 mg once daily
- Stop daily dosing when flare-up dosing begins
- Take with food preferably at the same time each day
- Adults and pediatric patients 14 years and older - flare-up dose
- 20 mg once daily for 4 weeks, followed by 10 mg once daily for 8 weeks (total of 12 weeks), even if symptoms resolve earlier, then return to 5 mg daily
- The 10 mg daily dosage may be extended in 4-week intervals until flare-up symptoms resolve
- If marked worsening or a new flare-up location occurs, restart the 12-week dosing at 20 mg daily
- Pediatric patients 8 to 13 years (females) and 10 to 13 years (males), 10 kg to 19.9 kg
- Daily 2.5 mg
- Week 1 to 4 flare-up 10 mg
- Week 5 to 12 flare-up 5 mg, all once daily
- Weight-based; with a moderate CYP3A inhibitor: 1 mg daily, 5 mg Weeks 1 to 4, 2.5 mg Weeks 5 to 12
- Pediatric patients 8 to 13 years (females) and 10 to 13 years (males), 20 kg to 39.9 kg
- Daily 3 mg
- Week 1 to 4 flare-up 12.5 mg
- Week 5 to 12 flare-up 6 mg, all once daily
- Weight-based; with a moderate CYP3A inhibitor: 1.5 mg daily, 6 mg Weeks 1 to 4, 3 mg Weeks 5 to 12
- Pediatric patients 8 to 13 years (females) and 10 to 13 years (males), 40 kg to 59.9 kg
- Daily 4 mg
- Week 1 to 4 flare-up 15 mg
- Week 5 to 12 flare-up 7.5 mg, all once daily
- Weight-based; with a moderate CYP3A inhibitor: 2 mg daily, 7.5 mg Weeks 1 to 4, 4 mg Weeks 5 to 12
- Pediatric patients 8 to 13 years (females) and 10 to 13 years (males), ≥ 60 kg
- Daily 5 mg
- Week 1 to 4 flare-up 20 mg
- Week 5 to 12 flare-up 10 mg, all once daily
- Weight-based; with a moderate CYP3A inhibitor: 2.5 mg daily, 10 mg Weeks 1 to 4, 5 mg Weeks 5 to 12 (also applies to patients ≥14 years and adults)
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION Obtain a negative pregnancy test in females of reproductive potential before initiation of SOHONOS ( 2.1 ) Recommended dosage includes a chronic daily dose, which can be increased for flare-up symptoms ( 2.2 ) For adults and pediatric patients 14 years and older: Recommended dosage is 5 mg once daily, with an increase in dose at the time of a flare-up to 20 mg once daily for 4 weeks, followed by 10 mg once daily for 8 weeks for a total of 12 weeks (20/10 mg flare-up treatment) ( 2.2 ) For pediatric patients under 14 years: Weight-adjusted for daily and flare-up dosing. Recommended daily dosage range from 2.5 to 5 mg. Refer to Table 1 in Full Prescribing Information for complete pediatric dosing ( 2.2 ) Take SOHONOS with food preferably at same time each day ( 2.3 ). Reduce the dose in the event of adverse reactions as appropriate ( 2.4 ) See Full Prescribing Information for complete dosing instructions ( 2 ) 2.1 Pregnancy Testing Prior to Treatment with SOHONOS For females of reproductive potential, obtain a negative pregnancy test within one week prior to initiating and periodically during SOHONOS therapy . If pregnancy occurs, stop SOHONOS treatment immediately and refer patient to an obstetrician/gynecologist experienced in reproductive toxicity. [see Warnings and Precautions (5.1) and Use in Specific Populations (8.1 , 8.3) ]. 2.2 Recommended Dosage and Duration Dosage Overview Take SOHONOS with food preferably at the same time each day [see Dosage and Administration (2.3) ] . The recommended dosing for SOHONOS includes a chronic daily dosage (daily dose) which can then be modified/increased in the event of FOP flare-up symptoms (flare-up dose). Initiate flare-up treatment at the onset of the first symptom indicative of a FOP flare-up or substantial high-risk traumatic event likely to lead to a flare-up (e.g., surgery, intramuscular immunization, mandibular blocks for dental procedures, muscle fatigue, blunt muscle trauma from bumps, bruises, falls, or influenza-like viral illnesses). Symptoms of a FOP flare-up typically include but are not limited to localized pain, soft tissue swelling/inflammation, redness, warmth, decreased joint range of motion, and stiffness.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Palovarotene side effects
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Most people have skin and dryness side effects. Common ones include:
Common side effects
- Dry skin
- Dry or chapped lips
- Joint pain
- Itching
- Pain in arms or legs
- Rash
- Hair loss
- Dry eyes
- Itching, rash, redness and skin peeling
- Joint, muscle, back and limb pain
- Headache and nausea
- Swelling in the hands or feet, and tiredness
When to get medical help
- Call your doctor right away if you think you might be pregnant.
- Tell your doctor about new or worsening depression, anxiety, mood changes or thoughts of suicide.
- Get medical attention for any vision problems, including trouble seeing at night.
- Report slowed growth in height in a child, or new back pain, which may signal a spine fracture.
- Report skin that is cracked, peeling or infected, or a bad sunburn-type reaction.
- Seek help for signs of an allergic reaction.
Call your doctor about mood changes or suicidal thoughts, vision changes, signs of skin infection, slowed growth in a child, or back pain.
Palovarotene warnings and precautions
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- Pregnancy: it can cause birth defects and must not be used during pregnancy.
- Growth in children: it can cause irreversible early closing of growth plates, so growth is monitored.
- Skin and eyes: dryness is very common, and it can raise sun sensitivity and skin infection risk.
- Bones: it can lower spine bone density and raise the risk of spine fractures.
- Mental health: depression, anxiety, mood changes and suicidal thoughts have been reported.
- Night blindness: be careful driving at night.
Palovarotene interactions
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Several drugs and foods can change how palovarotene works or add to its risks.
- CYP3A4 inhibitors: raise levels and side effect risk.
- CYP3A4 inducers: lower levels and may reduce effectiveness.
- Vitamin A above the daily allowance and other oral retinoids: risk of too much vitamin A.
- Tetracycline antibiotics: risk of raised pressure around the brain.
- Grapefruit, pomelo and their juices: avoid.
Interactions listed in the FDA-approved label
From the Palovarotene prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Strong CYP3A4 inhibitors: Increased exposure of palovarotene, which may increase the risk of SOHONOS adverse reactions. Avoid concomitant use of a strong CYP3A4 inhibitor during SOHONOS treatment.
- Moderate CYP3A4 inhibitors: May increase the exposure of palovarotene, which may increase the risk of SOHONOS adverse reactions. Avoid concomitant use if possible; if co-administration will occur, reduce the SOHONOS dose by half.
- Strong CYP3A4 inducers: Decreased the exposure of palovarotene, which may reduce the effectiveness of SOHONOS. Avoid concomitant use of strong CYP3A4 inducers with SOHONOS.
- Moderate CYP3A4 inducers: May decrease palovarotene exposure, which may reduce the effectiveness of SOHONOS. Avoid concomitant use of moderate CYP3A4 inducers with SOHONOS.
- Vitamin A and other oral retinoids: Palovarotene is in the same pharmacological class as vitamin A, so use together may lead to additive effects and risk of hypervitaminosis A. Avoid vitamin A in doses higher than the recommended daily allowance (RDA) and/or other oral retinoids with SOHONOS.
- Tetracyclines: Systemic retinoid use has been associated with cases of benign intracranial hypertension (pseudotumor cerebri), some involving concomitant tetracyclines. Avoid coadministration of SOHONOS with tetracycline derivatives.
- Systemic corticosteroids (prednisone): No clinically significant drug-drug interaction is expected when SOHONOS is co-administered with prednisone.
Read the label’s full interactions text
7 DRUG INTERACTIONS CYP3A4 Inhibitors: May increase SOHONOS exposure. Avoid concomitant use of strong/moderate CYP3A4 inhibitors. If concomitant use of moderate CYP3A4 inhibitors is unavoidable, reduce the dose of SOHONOS by half ( 2.5 , 7.1 ) CYP3A4 Inducers: May decrease SOHONOS exposure. Avoid concomitant use of strong/moderate CYP3A4 inducers ( 7.1 ) Vitamin A: May cause additive effects ( 7.2 ) Tetracyclines: Avoid concomitant use with SOHONOS ( 7.3 ) Systemic Corticosteroids: No clinically significant drug interaction is expected with concomitant use of SOHONOS ( 7.4 ) 7.1 Effect of Other Drugs on SOHONOS Clinically significant drug interactions affecting the exposure of SOHONOS are listed in Table 6. Table 6. Drugs that affect exposure of SOHONOS. Strong CYP3A Inhibitors Clinical Impact Co-administration of SOHONOS with strong CYP3A4 inhibitors increased the exposures of palovarotene [see Clinical Pharmacology (12.3) ] , which may increase the risk of SOHONOS adverse reactions. Prevention or Management Avoid concomitant use of a strong CYP3A4 inhibitor during SOHONOS treatment [see Dosage and Administration (2.5) ] . Moderate CYP3A Inhibitors Clinical Impact Co-administration of SOHONOS with moderate CYP3A4 inhibitors may increase the exposure of palovarotene [see Clinical Pharmacology (12.3) ] , which may increase the risk of SOHONOS adverse reactions. Prevention or Management Avoid concomitant use of a moderate CYP3A4 inhibitor with SOHONOS, if possible. If co-administration will occur, reduce the SOHONOS dose by half when co-administered with moderate CYP3A inhibitors [see Dosage and Administration (2.5) ] . Strong CYP3A Inducers Clinical Impact Co-administration of SOHONOS with strong CYP3A4 inducers decreased the exposure of palovarotene [see Clinical Pharmacology (12.3) ] , which may reduce the effectiveness of SOHONOS. Prevention or Management Avoid concomitant use of strong CYP3A4 inducers with SOHONOS. [see Dosage and Administration (2.5) ] .
Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Palovarotene
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- Not for use in pregnancy. A pregnancy test and effective contraception are required for females who can become pregnant.
- Do not breastfeed during treatment and for at least 1 month after.
- Do not donate blood during treatment and for 1 week after.
- Not for anyone allergic to retinoids.
- Growing children need baseline and ongoing growth and bone checks.
- Not recommended in severe kidney impairment or moderate to severe liver impairment.
- Tell your doctor about any psychiatric history.
Palovarotene overdose
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No overdose experience has been reported. Because palovarotene is related to vitamin A, an overdose could cause signs of too much vitamin A, such as severe headache, nausea or vomiting, drowsiness, irritability and itching. Treatment is supportive care based on symptoms.
What Palovarotene does in the body
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At doses up to 2.5 times the maximum recommended dose, palovarotene does not meaningfully prolong the QT interval, a measure of the heart's electrical cycle.
How your body processes Palovarotene
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Palovarotene reaches peak levels about 3 to 4 hours after a dose, and steady levels are reached by about day 3 of daily dosing. Food raises how much is absorbed, which is why it is taken with food. It is broken down mainly by the liver enzyme CYP3A4 and cleared mostly in the stool. Its half-life is about 8.7 hours.
How to store Palovarotene
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Keep out of reach of children. Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) . protect from light.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Palovarotene
138 supplements and herbal products have documented interactions with Palovarotene in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 3
- Moderate · 94
- Minor · 41
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Palovarotene: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Palovarotene — the kind of thing our pharmacy team would talk through with you at the counter.
What is this medicine for?
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How should I take it?
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What side effects should I expect?
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Is it safe in pregnancy?
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Is it safe for my child?
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What should I call my doctor about?
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Is Palovarotene available over the counter?
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When was Palovarotene first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Palovarotene on HelloPharmacist
Palovarotene forms and strengths (how it comes)
Palovarotene is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Palovarotene inactive ingredients by manufacturer.
Capsule
How this form is used
- Sohonos is used to reduce new heterotopic ossification in adults and in children aged 8 and older (females) or 10 and older (males) with FOP.
- Sohonos is taken once daily with food, preferably at the same time each day.
- Sohonos capsules may be swallowed whole or opened and sprinkled on a teaspoon of soft food, then taken within 1 hour.
- Do not take Sohonos with grapefruit, pomelo or their juices.
- If a Sohonos dose is missed by more than 6 hours, skip it. Never take two doses in the same day.
Palovarotene on the U.S. market: products, makers and brands
How Palovarotene appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 5 Palovarotene product records with the FDA, mostly as capsule; the earliest marketing or approval year on record is 2022. Brand names on the directory include Sohonos; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (2) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Compare Palovarotene products
A representative set of FDA-listed product records for Palovarotene — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Capsule | ||||
| 1 mg | Oral | Ipsen Biopharmaceuticals, Inc. | NDA | View NDC → |
| 1.5 mg | Oral | Ipsen Biopharmaceuticals, Inc. | NDA | View NDC → |
| 2.5 mg | Oral | Ipsen Biopharmaceuticals, Inc. | NDA | View NDC → |
| 5 mg | Oral | Ipsen Biopharmaceuticals, Inc. | NDA | View NDC → |
| 10 mg | Oral | Ipsen Biopharmaceuticals, Inc. | NDA | View NDC → |
Showing 5 of 5 products — FDA National Drug Code Directory. See every product, package size and price: browse all 5 Palovarotene NDCs →
Palovarotene side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Palovarotene — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Palovarotene in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Palovarotene FDA approval history
How Palovarotene went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Palovarotene recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Palovarotene recalls since July 2021.
✅No Palovarotene recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2663954 1 dose form · 5 strengths
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Dose form (SCDF) Oral Capsule RxCUI 2663959In current FDA listings
Look up RxCUI 2663954 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Palovarotene supply and shortage status
Whether Palovarotene is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Palovarotene brand names
Palovarotene is sold under one brand name in the FDA directory — Sohonos. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Palovarotene: manufacturers and labelers
One company lists Palovarotene products with the FDA. By number of product records, the largest are Ipsen Biopharmaceuticals, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Palovarotene drug class (RxNorm)
Palovarotene belongs to the Retinoid class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Palovarotene page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Ipsen Biopharmaceuticals, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →