What the label lists and what reports show
Progesterone side effects
Progesterone's FDA label: “Overall, the most frequently reported treatment-emergent adverse reactions, reported in greater than or equal to 5 percent of subjects, were nausea, fatigue, vaginal mycosis, nasopharyngitis, upper respiratory tract infection, headache, dizziness, breast …” FAERS holds 22,737 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 headache (2,089 reports).
- Generic listed
- A presentation discontinued
Check it at the source: the progesterone FDA label on DailyMed (effective July 23, 2026, Acertis Pharmaceuticals, LLC); 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 PROMETRIUM Capsules?Side effects are grouped by how serious they are and how often they happen when you are treated: Serious, but less common side effects include: • Risk to the Fetus: Cases of cleft palate, cleft lip, hypospadias, ventricular septal defect, patent ductus arteriosus, and other congenital heart defects. • Abnormal Blood Clotting: Stroke, heart attack, pulmonary embolus, visual loss or blindness. Some of the warning signs of serious side effects include: • Changes in vision or speech • Sudden new severe headaches • Severe pains in your chest or legs with or without shortness of breath, weakness and fatigue • Dizziness and faintness • Vomiting Call your healthcare provider right away if you get any of these warning signs, or any other unusual symptoms that concern you. […]
Source: FDA drug label, Acertis Pharmaceuticals, LLC, effective July 23, 2026 (SPL set 1cf237ff-c4f8-4faa-a7aa-77599c856889), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsOverall, the most frequently reported treatment-emergent adverse reactions, reported in greater than or equal to 5 percent of subjects, were nausea, fatigue, vaginal mycosis, nasopharyngitis, upper respiratory tract infection, headache, dizziness, breast tenderness, abdominal distension, acne, dysmenorrhea, mood swing, and urinary tract infection.
TABLE 7. Adverse Reactions (≥ 2%) Reported in an 875 Patient Placebo-Controlled Trial in Postmenopausal Women Over a 3-Year Period [Percentage (%) of Patients Reporting]
| Reaction | PROMETRIUM Capsules 200 mg with Conjugated Estrogens 0.625 mg (n=178) | Placebo (n=174) |
|---|---|---|
| Headache | 31 | 27 |
| Breast Tenderness | 27 | 6 |
| Joint Pain | 20 | 29 |
| Depression | 19 | 12 |
| Dizziness | 15 | 9 |
| Abdominal Bloating | 12 | 5 |
| Hot Flashes | 11 | 35 |
| Urinary Problems | 11 | 9 |
| Abdominal Pain | 10 | 10 |
| Vaginal Discharge | 10 | 3 |
| Nausea / Vomiting | 8 | 7 |
| Worry | 8 | 4 |
| Chest Pain | 7 | 5 |
| Diarrhea | 7 | 4 |
| Night Sweats | 7 | 17 |
| Breast Pain | 6 | 2 |
| Swelling of Hands and Feet | 6 | 9 |
| Vaginal Dryness | 6 | 10 |
| Constipation | 3 | 2 |
| Breast Carcinoma | 2 | <1 |
| Breast Excisional Biopsy | 2 | <1 |
| Cholecystectomy | 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.
From the label: adverse reactions, continuedSee WARNINGS and PRECAUTIONS . 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 the clinical trials of another drug and may not reflect the rates observed in practice. In a multicenter, randomized, double-blind, placebo-controlled clinical trial, the effects of PROMETRIUM Capsules on the endometrium was studied in a total of 875 postmenopausal women. Table 7 lists adverse reactions greater than or equal to 2 percent of women who received cyclic PROMETRIUM Capsules 200 mg daily (12 days per calendar month cycle) with 0.625 mg conjugated estrogens or placebo. TABLE 7.
Source: FDA drug label, Acertis Pharmaceuticals, LLC, effective July 23, 2026 (SPL set 1cf237ff-c4f8-4faa-a7aa-77599c856889), via openFDA; the full label on DailyMed
What do FAERS reports show?
22,737 reports list progesterone among the medicines taken, each a report of something that happened, not proof the medicine caused it; 504 are coded as a death and 3,636 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 19 reactions below, 11 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?
- Progesterone: 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