“You’re not ugly. You just have cortisol face,” Mandana Zarghami told viewers at the start of a recent TikTok video , one of many on the social platform blaming a rounded, puffy face on high levels of the hormone. Hundreds of lifestyle and beauty influencers have claimed online that they’ve transformed their appearance by tackling stress.

Many are sharing before and after photos that contrast their once fuller faces with new, lean jawlines, attributing the difference to lower levels of cortisol, the hormone produced in response to physical and mental stress. Some are even selling products and programmes they claim will reduce cortisol and lead to a slimmed-down appearance. Zarghami, 28, said in an interview that her aim on TikTok was to educate people about the effects of high cortisol, though she does have a wellness business, through which she sells a “hormone-balance tea”.

When she began experiencing visible swelling of her face and abdomen in 2020, Zarghami consulted a doctor, who suggested stress might be to blame. She felt frustrated by the response: “How can I control my stress if you’re not giving me tools?” she wondered. Zarghami made lifestyle changes that she believed had reduced both her cortisol level and her persistent facial swelling.

These included drinking diluted apple cider vinegar after waking, and then green tea throughout the day. She also stopped weight lifting and instead started doing low-impact exercise and walking. Zarghami later s.