The product 'Jia Yi Jian' was recently seized by the Medicines and Healthcare products Regulatory Agency (MHRA) and claimed to contain only herbal ingredients.
However, laboratory analysis revealed the unlicensed product contained up to four times the level of pharmaceuticals found in legally prescribed medicinal products licensed for the treatment of obesity and erectile dysfunction.
Manufactured by Hu Nan Aimin Pharmaceuticals Ltd, the undeclared ingredients could cause serious side effects including significant heart and blood pressure problems as well as adversely reacting with other prescription drugs such as those for blood pressure, heart disease and some antidepressants.
Richard Woodfield, MHRA Group Manager for Herbal Medicines, said people should consult their GP or a health care professional before taking herbal medication particularly for serious medical conditions such as obesity or erectile dysfunction.
"This product, adulterated with large and uncontrolled amounts of pharmaceutical substances, presents a clear risk to consumers.
"There is continuing evidence that some so-called 'herbal' products on the UK and international markets are nothing of the kind.
"Often, such marketing claims about the supposed natural ingredients in these unlicensed products are simply an attempt to divert the consumer's attention away from very low manufacturing and ethical standards.
"The MHRA has issued warnings previously about adulterated products supplied by some TCM outlets, but the problem is by no means limited to that sector.
"The safest method to obtain medication is to see a health care professional and have a proper diagnosis, especially as sometimes conditions such as erectile dysfunction can be the symptom of something more serious."
The MHRA advise anyone using this product to stop taking it immediately and consult their GP or a healthcare professional.