A middle aged woman was admitted to Salisbury District Hospital after she was found to be severely hyponatraemic by her GP. She had been suffering from lightheadedness, headaches and tiredness for a few weeks before her admission but there was no obvious aetiology. Her past medical history included hypertension but she was not on diuretics or any other medication that could affect her sodium levels. Her serum sodium at the GP surgery was 123 and when she was admitted in the Acute Medical Unit in Salisbury District Hospital it was 122. Her baseline serum sodium levels were between 132 and 134 in the past. Her clinical examination was normal. There was no evidence of fluid overload or dehydration. She was diagnosed with symptomatic euvolaemic hyponatraemia. She had never had hyponatraemia in the past. There was no history of smoking, excess alcohol consumption or excessive oral fluid consumption. The patient did mention she had started taking an over the counter drug to reduce her anxiety and improve her sleep. That substance included valerian extract (KALMS, https://www.kalmsrange.com/kalms-range/). She was using it regularly during the day 34 times. Her creatinine, urea and eGFR were normal. The rest of the electrolytes, the thyroid function tests and the cortisol levels were also normal. Her serum osmolality was low, her urine osmolality was high and the urine sodium level was 21. She was managed with oral sodium tablets, fluid restriction up to 1.5 l per day and monitoring of her sodium levels. She was advised to stop the valerian extract containing product. After 4 days of admission, her sodium levels normalised, her symptoms disappeared and she was discharged home. A week after her discharge her sodium levels remained normal after having being checked again at her GP Surgery.