A teaching assistant who turned to weight loss injections to transform her life has been left a virtual recluse after accidentally overdosing on supplements. Charlotte Foster, 36, from Pontypridd, Wales, thought she was nourishing her body, but she was unknowingly consuming a toxic cocktail of vitamins that left her in constant agony with weeping, swollen skin.
From Weight Loss to Health Crisis
Charlotte began taking Mounjaro in October 2024, paying £200 a month for a private prescription to address back pain and sluggishness. Starting at 16 stone, she lost two stone within two months and felt her confidence returning. However, her social media feed became flooded with weight loss influencers claiming supplements were mandatory for anyone on GLP-1 injections. Struggling with hair loss after shedding weight, she decided to follow their advice.
"I was following loads of influencers online who were saying if you take Mounjaro, you have to take all these different supplements," Charlotte told the Mirror. "I was taking around 10 different supplements a day... multivitamins, B12, D3, K2, gummies, cortisol support, fibre, and gut health. Literally anything I saw on TikTok."
The Onset of Symptoms
By February 2025, the cocktail of supplements—costing her £50 a month—began to backfire. It started with a tiny dry patch under her eyebrows, just four months after starting the jabs, but quickly escalated into a chronic, painful condition. Her skin developed large, burning dry patches, and even crying would cause her skin to turn red. Blood tests revealed dangerously high vitamin levels across the board.
"I didn't even know you could overdose on them," she admitted. "It's obviously my fault but it's so easy to be influenced on TikTok. Overdosing on supplements is a real thing, and the side effects can be quite nasty."
Life Disrupted
Charlotte now relies on steroid creams and has had to cancel work and social plans due to severe flare-ups. "When the flare-ups are bad, my skin weeps and becomes swollen. It's very painful so it stops me leaving the house. I have had to cancel plans and have even missed work because of it," she added. "I love wearing makeup, but now I can't as much as I used to."
Expert Warnings
Officials warn that Charlotte's story is becoming increasingly common as weight loss jab users turn to unregulated online advice. Dr Suzanne Wylie, a GP for IQdoctor, expressed serious concern over patients "self-prescribing" without clinical assessment. "Fat-soluble vitamins such as A, D, E and K can accumulate in the body and become toxic if taken excessively," Dr Wylie warned. "Taking unnecessary or excessive supplements can lead to toxicity, delayed medical treatment and avoidable health complications."
Superintendent Pharmacist Kishan Purohit notes that while Mounjaro suppresses appetite, reducing natural nutrient intake, supplements are rarely needed if the user maintains a balanced diet.
Ongoing Health Issues
More than a year after her first flare-up, Charlotte remains under hospital dermatologist care and takes steroids. Her Mounjaro journey ended abruptly in February when she developed kidney stones and a hiatus hernia, requiring hospitalization. "They couldn't say it was definitely down to the Mounjaro. Although it has been great for me and great I've lost so much weight, it also has long-term impacted my health with regards to my skin and now my tummy with the hernia," she said.
Charlotte now shares her experience on TikTok @charlottefoster3, urging people to only take supplements their body actually needs. "I can't hide my face," she said. "I am the type of girl who would never leave the house without makeup on but now I've had to strip it right back."
TikTok Influence on Supplements
With just a few swipes on TikTok, users can be inundated with advice from fellow weight loss jab users on what supplements to take. One creator shared a video of her "best supplements," recommending digestive enzymes to her followers. According to the NHS, most people get all necessary nutrients from a varied, balanced diet, though some may require extra supplements.
Dr Wylie added: "There is also a misconception that because these medications [GLP-1] can cause side effects such as nausea, fatigue or constipation, supplements marketed online as 'support stacks' are medically necessary, when in reality many side effects are better managed through careful dose adjustment, hydration, dietary advice and medical supervision."
She strongly encourages anyone taking weight loss injections to consult a GP, pharmacist, or dietitian before starting supplements, especially high-dose products or multiple formulations.
