What the label lists and what reports show
Megestrol side effects
Megestrol's FDA label lists its adverse reactions in its own words. FAERS holds 3,841 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 (352 reports).
- Generic listed
Check it at the source: the megestrol FDA label on DailyMed (effective April 22, 2022, Strides Pharma Science Limited); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsClinical Adverse Events: Adverse events which occurred in at least 5% of patients in any arm of the two clinical efficacy trials and the open trial are listed below by treatment group. All patients listed had at least one post baseline visit during the 12 study weeks. These adverse events should be considered by the physician when prescribing megestrol acetate oral suspension. ADVERSE EVENTS% of Patients Reporting Trial 1 (N = 236) Trail 2 (N=87) Open Label Trial Megestrol Acetate mg/day No. of Patients Placebo 0 N=34 100 N=68 400 N=69 800 N=65 Placebo 0 N=38 800 N=49 1200 N=176 Diarrhea 15 13 8 15 8 6 10 Impotence 3 4 6 14 0 4 7 Rash 9 9 4 12 3 2 6 Flatulence 9 0 1 9 3 10 6 Hypertension 0 0 0 8 0 0 4 Asthenia 3 2 3 6 8 4 5 Insomnia 0 3 4 6 0 0 1 Nausea 9 4 0 5 3 4 5 Anemia 6 3 3 5 0 0 0 Fever 3 6 4 5 3 2 1 Libido Decreased 3 4 0 5 0 2 1 Dyspepsia 0 0 3 3 5 4 2 Hyperglycemia 3 0 6 3 0 0 …
ADVERSE EVENTS % of Patients Reporting
This table is printed in the Megestrol Acetate label published by Precision Dose Inc. of March 28, 2024; the label quoted above does not print one.
| Megestrol Acetate mg/day No. of Patients | Placebo 0 N=34 | 100 N=68 | 400 N=69 | 800 N=65 | Placebo 0 N=38 | 800 N=49 | Label Trial 1200 N=176 |
|---|---|---|---|---|---|---|---|
| Diarrhea | 15 | 13 | 8 | 15 | 8 | 6 | 10 |
| Impotence | 3 | 4 | 6 | 14 | 0 | 4 | 7 |
| Rash | 9 | 9 | 4 | 12 | 3 | 2 | 6 |
| Flatulence | 9 | 0 | 1 | 9 | 3 | 10 | 6 |
| Hypertension | 0 | 0 | 0 | 8 | 0 | 0 | 4 |
| Asthenia | 3 | 2 | 3 | 6 | 8 | 4 | 5 |
| Insomnia | 0 | 3 | 4 | 6 | 0 | 0 | 1 |
| Nausea | 9 | 4 | 0 | 5 | 3 | 4 | 5 |
| Anemia | 6 | 3 | 3 | 5 | 0 | 0 | 0 |
| Fever | 3 | 6 | 4 | 5 | 3 | 2 | 1 |
| Libido Decreased | 3 | 4 | 0 | 5 | 0 | 2 | 1 |
| Dyspepsia | 0 | 0 | 3 | 3 | 5 | 4 | 2 |
| Hyperglycemia | 3 | 0 | 6 | 3 | 0 | 0 | 3 |
| Headache | 6 | 10 | 1 | 3 | 3 | 0 | 3 |
| Pain | 6 | 0 | 0 | 2 | 5 | 6 | 4 |
| Vomiting | 9 | 3 | 0 | 2 | 3 | 6 | 4 |
| Pneumonia | 6 | 2 | 0 | 2 | 3 | 0 | 1 |
| Urinary Frequency | 0 | 0 | 1 | 2 | 5 | 2 | 1 |
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.
Source: FDA drug label, Strides Pharma Science Limited, effective April 22, 2022 (SPL set 9f7365a0-67cf-45fc-a914-e40a4507a063), via openFDA; the full label on DailyMed
What do FAERS reports show?
3,841 reports list megestrol among the medicines taken, each a report of something that happened, not proof the medicine caused it; 956 are coded as a death and 1,783 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 23 reactions below, 10 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?
- Megestrol: 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