Man boobs, panic and diarrhea: The embarrassing side effects of the 'Superman supplements'

They're the supermarket supplements that men hope can turn them into Superman.

Tales abound on internet bodybuilding chatrooms and men's health forums about wonder supplements that can improve everything from their sexual prowess to exercise stamina.

Millions of men take dietary supplements daily, despite a groundbreaking 2013 US study finding them to be unnecessary.

But some could be even worse than pointless - they could be causing everything from diarrhea to panic attacks.

Here is what you need to know about some of the most popular supplements marketed towards men.

What is it supposed to do? Derived from the bark of a West African tree, yohimbine is marketed as a treatment for erectile dysfunction (ED), to boost for sexual function and aid weight loss.

But this innocent-looking pill is the one supplement that Dr Giorgianni warns should be avoided “particularly if you are over 50 or have any cardiovascular conditions.”

Potential side effects: Can include rapid heart rate, overstimulation, cold sweats and insomnia.

What is it supposed to do? A member of the amino acid family of organic compounds, L-Arginine is converted into nitric oxide in the body which helps blood vessel relax, and in turn helps blood flow to the penis. It is also sold to prevent colds and improve sporting performance.

Unless it is prescribed by a doctor, for instance to treat specific heart and blood vessel conditions, the body can absorb enough L-Arginine from foods including red meat, poultry, fish, and dairy products.

What are the potential side effects? Those who take L-Arginine without consulting their doctor risk exacerbating conditions including asthma, cirrhosis, allergies, low blood pressure. It has also been linked to increasing heart attack risk, and creating a life-threating irregular heartbeat in those with kidney disease, according to WebMD.

What is it supposed to do? This mineral is tipped to protect against prostate problems, boost the immune system to help users train harder at the gym, and raise testosterone which is linked to muscle gain growth.

While taking zinc is not harmful for more people, only very small amounts are needed maintain health. Doses of around 40mg or less are safe. But studies show that taking more than 100mg a day for over a decade doubles the risk of prostate cancer.

What are the potential side effects? Taken in high dose, zinc can cause flu-like symptoms including a fever, coughing, stomach pain and fatigue. In serve cases it can trigger jaundice, which can occur due to liver damage.

What is it supposed to do? Taken as a powder in water, creatine is a naturally occuring acid that supplies muscles with energy, increase lean muscle mass, and help the body recover more quickly after exercise.

What are the potential side effects? Creatine has been deemed safe in recommended doses for adults who are healthy. However, anecdotal evidence suggests that is could have adverse side effects for those with kidney disease and asthma, Dr Pascale Kippelen, Senior Lecturer in Exercise and Respiratory Physiology at Brunel University recently told The Independent.

What is it supposed to do? Derived from the fruit, leaves or root of the Mediterranean tribulus terrestris plant, or punctured vine, this supplement is taken in the hope it will boost athletic performance or lessen the symptoms of angina and sexual dysfunction.

What are the potential side effects? The evidence to support its use is thin on the ground, and it has been linked to side effects including insomnia, prostate issues, and lowering “good” cholesterol.

What is it supposed to do? Men take the DHEA – a hormone produced in the kidneys which declines with age - for a range of conditions, from boosting libido and energy levels, to slowing ageing, improving mood, and strengthening muscles. It can be taken orally, or applied to the skin.

Unfortunately, scientific evidence does not support its status as a solve-all pill.

What are the potential side effects? Reported side effects include so-called “man boobs” as well as changing how insulin works, meaning it can be risky for those with diabetes. As it can affect how estrogen operates, it can also impact certain types of cancer.