Food standards authority NVWA has urged retailers to withdraw a herbal paste from sale that contains the active ingredient in Viagra.

Research from Germany found that two teaspoons of Epimedyumlu Macun – marketed under brand names including Vi-Max Male and Power Honey – contains the same amount of sildenafil as one Viagra pill.

Some online retailers even promote the honey as a ‘natural aphrodisiac’.

The chemical is banned for non-medical use and the NVWA warned that it could cause side-effects including heart problems, diarrhoea and blurred vision.

Mainstream online retailers including bol.com and Marktplaats have already withdrawn the product from sale, but the agency said it could not monitor all internet sales channels. It also said it had found the honey in stock in four sellers of Turkish goods.