What the label lists and what reports show
Osilodrostat side effects
Osilodrostat's FDA label: “Most common adverse reactions (incidence > 20%) are adrenal insufficiency, fatigue, nausea, headache, edema, decreased appetite, arthralgia, myalgia, and diarrhea ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Recordati Rare Diseases Inc.” FAERS holds 2,082 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fatigue (289 reports).
- No generic listed
Check it at the source: the osilodrostat FDA label on DailyMed (effective November 18, 2025, Recordati Rare Diseases, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of ISTURISA?ISTURISA may cause serious side effects, including: See " What is the most important information I should know about ISTURISA? " Increase in other adrenal hormone levels. Your other adrenal hormones may increase when you take ISTURISA. Your healthcare provider may monitor you for the symptoms associated with these hormonal changes while you are taking ISTURISA: Low potassium (hypokalemia). High blood pressure (hypertension). Swelling (edema) in the legs, ankles or other signs of fluid retention. Excessive facial or body hair growth (hirsutism). Acne (in women). Call your healthcare provider if you have any of these side effects. […]
Source: FDA drug label, Recordati Rare Diseases, Inc., effective November 18, 2025 (SPL set f3a5ec24-63c3-4d83-b1c0-6c550fbe7ae2), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence > 20%) are adrenal insufficiency, fatigue, nausea, headache, edema, decreased appetite, arthralgia, myalgia, and diarrhea ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Recordati Rare Diseases Inc.
Table 1: Adverse Reactions With a Frequency of More Than 10% in 48-week Clinical Study 1 in Adults with Cushing's Disease
| Adverse Reaction Type | (N = 137) % |
|---|---|
| Adrenal insufficiency Adrenal insufficiency includes glucocorticoid deficiency,… | 43.1 |
| Fatigue Fatigue includes lethargy, asthenia. | 38.7 |
| Nausea | 37.2 |
| Headache Headache includes head discomfort. | 30.7 |
| Edema Edema includes edema peripheral, generalized edema, localized edema. | 21.2 |
| Nasopharyngitis | 19.7 |
| Vomiting | 19 |
| Arthralgia | 17.5 |
| Back pain | 15.3 |
| Rash Rash includes rash erythematous, rash generalized, rash maculopapular, rash papular. | 15.3 |
| Diarrhea | 14.6 |
| Blood corticotrophin increased | 13.9 |
| Dizziness Dizziness includes dizziness postural. | 13.9 |
| Abdominal pain Abdominal pain includes abdominal pain upper, abdominal discomfort | 13.1 |
| Hypokalemia Hypokalemia includes blood potassium decreased. | 12.4 |
| Myalgia | 12.4 |
| Decreased appetite | 11.7 |
| Hormone level abnormal | 11.7 |
| Hypotension Hypotension includes orthostatic hypotension, blood pressure decreased, blood… | 11.7 |
| Urinary tract infection | 11.7 |
| Blood testosterone increased | 10.9 |
| Pyrexia | 10.9 |
| Anemia | 10.2 |
| Cough | 10.2 |
| Hypertension | 10.2 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedClinically significant adverse reactions that appear in other sections of the labeling include: Hypocortisolism [see Warnings and Precautions (5.1) ] QT Prolongation [see Warnings and Precautions (5.2) ] Elevations in Adrenal Hormone Precursors and Androgens [see Warnings and Precautions (5.3) ] Most common adverse reactions (incidence > 20%) are adrenal insufficiency, fatigue, nausea, headache, edema, decreased appetite, arthralgia, myalgia, and diarrhea ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Recordati Rare Diseases Inc. at 1-888-575-8344 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in clinical trials of another drug and may not reflect the rates observed in practice. The safety of ISTURISA was evaluated in two clinical trials in adults with Cushings disease. Study 1 (NCT02180217) was a 4-period, multicenter study with a 12-week open-label titration period, 12-week open-label maintenance period, 8-week double-blind, placebo-controlled period, and 14 to 24-week open label treatment period in 137 patients with Cushing's disease. …
Source: FDA drug label, Recordati Rare Diseases, Inc., effective November 18, 2025 (SPL set f3a5ec24-63c3-4d83-b1c0-6c550fbe7ae2), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,082 reports list osilodrostat among the medicines taken, each a report of something that happened, not proof the medicine caused it; 270 are coded as a death and 737 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 14 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Osilodrostat: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions