Key takeaways:
- The FDA granted an Investigational Device Exemption approval for FemBloc to begin the final phase of its pivotal FINALE trial.
- FemBloc offers a non-surgical, permanent birth control option that requires no anesthesia, incisions, or recovery time.
- The device works by inserting a polymer into the fallopian tubes, which safely degrades and promotes natural scar tissue formation for blockage.
- Clinical trial data showed a 99.6% procedural success rate and a 0% pregnancy rate, with no serious adverse events reported.
- FemBloc has already received full regulatory approval in Europe, the United Kingdom, and New Zealand, showing strong global momentum.
The FDA has granted an Investigational Device Exemption (IDE) approval for FemBloc, a non-surgical permanent birth control, to enroll in the final phase of the FINALE pivotal trial.1
This step follows the successful completion of Part A of the multi-stage trial design, marking a significant milestone toward FemBloc receiving US Pre-Market Approval. This would make FemBloc the first non-surgical permanent birth control to receive commercialization.
“This FDA IDE approval represents a critical milestone in advancing FemBloc toward US approval, bringing women a long overdue, non-surgical option for permanent birth control, as women in Europe and other select countries are now beginning to benefit from this important innovation,” said Kathy Lee-Sepsick, Chief Executive Officer and Founder of Femasys Inc.
How FemBloc works
FemBloc inserts a proprietary blended polymer into both fallopian tubes through a patented delivery system, allowing permanent blockage to occur through the formation of natural scar tissue after safe degradation. This provides a significant unmet need in women’s reproductive health.
There are no anesthesia, incisions, or recovery time involved with using Fembloc, allowing patients to avoid infection and other surgical complication risks. This makes Fembloc a safer, more convenient, and affordable first-of-its-kind option.
Fembloc was granted full regulatory approval in Europe in June of 2025, the United Kingdom in August of 2025, and New Zealand in September 2025. The initial clinical data evaluating Fembloc highlighted positive efficacy, 5-year safety, and satisfaction data.
Clinical trial overview
The data was obtained from 3 prospective, open-label, clinical trials performed at 25 US tertiary medical centers.2 Participants included women aged 21 to 45 years seeking permanent contraception and willing to use temporary contraception until documented bilateral tubal occlusion.
Those with prior tubal surgery or ectopic pregnancy, difficult cervical visualization, current or recent cervix, endometrium, or fallopian tube infection, suspected gynecological malignancy, known uterine anomaly, or pregnancy termination under 6 weeks from scheduled Fembloc procedure were excluded.
Three months after the FemBloc procedure, patients underwent a confirmation test. After another 3 months, adverse event assessments were performed. Finally, pregnancy and safety tests over phone call were performed 1 year after the confirmation test then annually for 2 to 5 years.
Efficacy and safety results
A successful FemBloc procedure was reported in 99.6% of the intention-to-treat population, 90.8% of whom had a completed confirmation test. Of participants, 79.9% were multiparous and 63.8% were using a hormonal contraceptive at the time of screening. A successful confirmation test was completed after approximately 3 months in most patients.
The pregnancy rate was significantly lower than the 6% performance goal, at 0%. Additionally, no serious adverse events, including uterine perforations or ectopic pregnancies, were reported. During the 5-year follow-up period, common adverse events among patients included:
- Vaginal spotting in 58.5%
- Pelvic or abdominal pain in 37.1%
- Abdominal or uterine cramps in 18.8%
- Nausea in 3.5%
- Muscoskeletal cramps in 2.6%
- Abdominal bloating in 1.3%
Of these events, 61.1% occurred on the day of the FemBloc procedure and 85.8% resolved within 3 days. Overall, the data highlighted minimally invasive delivery of the FemBloc permanent birth control system.
“In contrast to historic surgical sterilization, the FemBloc approach offers a non-surgical, more accessible alternative with fewer risks, contraindications, and likely at a substantially lower cost,” wrote investigators.
References
- Femasys secures FDA approval to advance final FemBloc® trial phase and $12 million financing, with potential to reach $58 million. Femasys. November 3, 2025. Accessed November 4, 2025. https://ir.femasys.com/news/news-details/2025/Femasys-Secures-FDA-Approval-to-Advance-Final-FemBloc-Trial-Phase-and-12-Million-Financing-with-Potential-to-Reach-58-Million/default.aspx.
- Liu JH, Blumenthal PD, Castano PM, et al. FemBloc non-surgical permanent contraception for occlusion of the fallopian tubes. Journal of Gynecology & Reproductive Medicine. 2025;9(1).
