What the label lists and what reports show
Secnidazole side effects
Secnidazole's FDA label: “Most common adverse reactions observed in clinical trials of bacterial vaginosis (incidence ≥ 2%) were vulvovaginal candidiasis, headache, nausea, dysgeusia, vomiting, diarrhea, abdominal pain, and vulvovaginal pruritus.” FAERS holds 281 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 vomiting (78 reports).
- No generic listed
Check it at the source: the secnidazole FDA label on DailyMed (effective February 19, 2025, Evofem 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 SOLOSEC?SOLOSEC can cause side effects including vaginal yeast infections. Symptoms of a vaginal yeast infection include white or yellowish discharge (discharge may be lumpy or look like cottage cheese) and vaginal itching. The most common side effects of SOLOSEC include headache, nausea, vomiting, diarrhea, abdominal pain, vaginal itching and a bad, bitter or metallic taste in your mouth (dysgeusia). These are not all of the possible side effects of SOLOSEC. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Source: FDA drug label, Evofem Inc., effective February 19, 2025 (SPL set 056485b6-8bba-4a21-ae00-cdb4e7ae4bfa), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions observed in clinical trials of bacterial vaginosis (incidence ≥ 2%) were vulvovaginal candidiasis, headache, nausea, dysgeusia, vomiting, diarrhea, abdominal pain, and vulvovaginal pruritus.
Table 1: Adverse Reactions Occurring (≥ 2 % SOLOSEC-Treated Patients) in the Pooled Placebo-Controlled Trials 1 and 2 in Adult Women with Bacterial Vaginosis
| Adverse Reaction | SOLOSEC N=197 n (%) | Placebo N=136 n (%) |
|---|---|---|
| Vulvovaginal candidiasis | 19 (9.6) | 4 (2.9) |
| Headache | 7 (3.6) | 2 (1.5) |
| Nausea | 7 (3.6) | 1 (0.7) |
| Diarrhea | 5 (2.5) | 1 (0.7) |
| Abdominal pain | 4 (2.0) | 2 (1.5) |
| Vulvovaginal pruritus | 4 (2.0) | 2 (1.5) |
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, continuedThe following important adverse reactions are discussed in greater detail in other sections of labeling: Vulvovaginal Candidiasis [Warnings and Precautions (5.1)] Bacterial Vaginosis: Most common adverse reactions observed in clinical trials of bacterial vaginosis (incidence ≥ 2%) were vulvovaginal candidiasis, headache, nausea, dysgeusia, vomiting, diarrhea, abdominal pain, and vulvovaginal pruritus. ( 6.1 ). Trichomoniasis: Most common adverse reaction observed in the clinical trial of trichomoniasis (incidence ≥ 2%) was vulvovaginal candidiasis. ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Evofem at toll-free-phone 1-833-EVFMBIO (1-833-383-6246) 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 the clinical trials of another drug and may not reflect the rates observed in practice. Bacterial Vaginosis The safety data described below reflect exposure to 629 patients, of whom 558 received a 2 g dose of SOLOSEC. SOLOSEC was evaluated in four clinical trials of female patients diagnosed with bacterial vaginosis: two placebo-controlled trials (Trial 1 n=215, Trial 2 n=189) and two uncontrolled safety trials (Trial 3 n=321, Trial 4 n=40). …
Source: FDA drug label, Evofem Inc., effective February 19, 2025 (SPL set 056485b6-8bba-4a21-ae00-cdb4e7ae4bfa), via openFDA; the full label on DailyMed
What do FAERS reports show?
281 reports list secnidazole among the medicines taken, each a report of something that happened, not proof the medicine caused it; 3 are coded as a death and 21 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, 7 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.
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?
- Secnidazole: 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