Women using weight-loss jabs have been warned by the UK's medicines regulator that they must use effective contraception.
The Medicines and Healthcare products Regulatory Agency (MHRA) says it is not known whether taking the medicines, such as Wegovy and Mounjaro, could harm an unborn baby.
It also warns that weight-loss jabs may make the contraceptive pill less likely to work in those who are overweight or obese.
There are concerns that the growing popularity of 'skinny jabs' means many women aren't using the drugs safely or getting the right advice.
It's thought the contraceptive pill may not be absorbed properly due to common side-effects of the jabs such as vomiting and diarrhoea, and because they slow the emptying of the stomach.
The MHRA says women should use contraception while taking GLP-1 medicines and for a certain period afterwards before trying to become pregnant – two months for Wegovy and Ozempic, and one month for Mounjaro.
It also advises that those using Mounjaro and taking an oral contraceptive should also use a condom for four weeks after starting the drug, or switch to another method such as the coil or implant.
Advice on contraception already appears in patient information leaflets that come with the medicines, but the MHRA has now issued its own guidance.
The drugs safety body says weight-loss injections must not be taken:
- during pregnancy
- while trying to get pregnant
- during breastfeeding
Women should be told this information when they starting taking the jabs, but there are fears the message is not getting through.
'It just wasn't expected'
Natasha Major, 26, started using Mounjaro to lose weight before planning to try for her third baby in a few years' time, but was shocked six weeks later to find she was pregnant. She was taking the contraceptive pill at the time.
"I have polycystic ovaries as well, so I can't get pregnant easily or quickly. So it was an even bigger shock that I had, which didn't make any sense to me," she says.
She then worried she could be harming the baby or it would not develop properly. Natasha rang her GP for advice and was told to stop taking it.
"We're over the initial shock now and really happy, just wasn't expected," she says.
"The last injection I took, I found out about the pregnancy three hours later and haven't taken it since then.
"I've had an early scan to make sure the pregnancy was viable and okay – baby had a little heartbeat and everything looks good," Natasha says.
The MHRA, as well as doctors and pharmacists, are worried that popular GLP-1 medicines, known as Wegovy, Mounjaro, Saxenda, Victoza and Ozempic, are not being used safely.
These prescription medicines, which are licensed to treat obesity (and Ozempic for type 2 diabetes), make people feel full by mimicking a hormone released after eating. Mounjaro also acts on another hormone linked to appetite and blood sugar control.
They are only available on the NHS to people with a very high BMI, but can also be bought privately from high street and online chemists. Such is the demand for the jabs, they are also being sold illegally on social media and from beauty salons, without any medical advice or prescription, as a quick fix to lose weight.
