The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has issued an alert urging women using weight-loss medications such as Ozempic, Wegovy, and Mounjaro to use effective contraception after receiving multiple reports of pregnancies among users, The Guardian reported on June 5, 2025.
The alert follows 40 reports of pregnancy in women taking these weight-loss drugs, prompting the MHRA to warn that Mounjaro, in particular, may reduce the effectiveness of oral contraceptives.
The agency advises that women taking this drug use barrier contraception, such as condoms, in addition to oral contraceptives, according to The Guardian.
The MHRA received 26 pregnancy-related reports concerning Mounjaro and an additional eight reports linked to semaglutide-based drugs (Ozempic and Wegovy).
Another weight-loss medication, Saxenda, which contains liraglutide, also garnered nine reports.
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While it’s unclear whether the pregnancies were unintended, some women confirmed their pregnancies were unplanned, as reported by The Guardian.
The MHRA has emphasised that these medications should not be used during pregnancy or while trying to conceive due to insufficient safety data regarding potential harm to a developing baby.
Women taking these drugs are also advised to continue contraception for up to two months after stopping the medication before attempting to become pregnant, as noted by the health agency.
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Dr. Channa Jayasena, a consultant in reproductive endocrinology, noted that GLP-1 medications like Ozempic and Wegovy are effective in aiding weight loss but could increase fertility in women with obesity by enhancing fertility.
However, these drugs may also interfere with the absorption of oral contraceptives, potentially increasing the risk of unintended pregnancies. This was also highlighted in The Guardian’s coverage.
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Dr. Alison Cave, the MHRA’s chief safety officer, urged patients not to misuse these medications for weight loss, stressing that they are licensed for specific medical conditions and not for cosmetic purposes.
She further recommended that patients read the provided patient information leaflets and consult healthcare professionals before using these powerful treatments, as reported in The Guardian.
