A TikTok video has sparked discussion about retatrutide, an experimental weight-loss drug, with claims it can 'make you fall out of love'. Users report 'emotional flattening', anhedonia, and feeling 'unbothered by 99% of everything'. The drug targets three appetite-related hormones and is still in clinical trials, but some are sourcing it illegally online.
Medical researchers are investigating whether these drugs act as a 'general reward dampener' by affecting the brain's reward centre, the mesolimbic system. This may reduce not only 'food noise' but also joy from other sources. Similar reports have emerged for approved GLP-1 drugs like Mounjaro, with a case report suggesting they can influence emotional regulation and potentially worsen depression.
Dr Naveed Asif, a GP from London General Practice, explained that GLP-1 medications affect smooth muscle activity, influencing arousability and orgasm due to changes in blood flow. He noted a dopaminergic component: dopamine may decrease, impacting desire and sexual attraction. Oestrogen balance may also be disrupted, leading to emotional disturbances, particularly in women.
Professor Paul Kenny, a neuroscientist at the Icahn School of Medicine, described the widespread use of GLP-1 drugs as a 'huge experiment'. He said it would not surprise him if medications tied to energy systems also shaped emotions and social interactions, as energy balance can modify behaviour, such as territoriality in animals.
