Viagra pills are often bought over the Internet
It is estimated that two million Britons are currently buying drugs over the internet and doctors are increasingly having to treat them for bad side effects.
In this week's Scrubbing Up, the chairman of the Royal College of GPs, Professor Steve Field, says the only way for anyone to safely buy drugs this way is to talk to their GP or pharmacist first.
GPs have always known that medication bought from the internet is a potential minefield and recent studies are showing just how risky it is.
A shocking survey has confirmed this is a major problem.
A poll in GP magazine found that one in four GPs have treated patients for adverse reactions to medicines they have brought online.
In addition, 85% of doctors surveyed believe there needs to be more regulation.
Products bought online can do harm even if they are the genuine article
Whatever the true scale of the problem, the danger of buying drugs from a non-professional source is obvious.
Counterfeit medication is common, and you just do not know what is going to be in those little pills - it could be anything from sugar to rat poison.
Products bought online can do harm even if they are the genuine article.
Side effect risk
The medication might be impure and have a higher dosage than expected, and the risk of side effects, overdose and/or interaction with other medication is worrying.
For example, weight loss drugs have clear criteria for pharmacists to sell or GPs prescribe.
They should only be used by patients with a certain body mass index and have to be used in conjunction with a healthy diet and exercise.
The absorption of fat soluble vitamins can have nasty side-effects and could be abused by children or those with eating disorders.
Another risk is that research and testing on drugs can throw up new evidence on drugs, but that information can be slow to reach the general public.
In my own practice I have seen young men who have ordered steroids online without knowing the full effects and are suffering health problems as a result.
The same goes for ordering Viagra online.
Patients might not know what dose they have taken, and it can interact with other drugs to have side effects which can include raising blood pressure, headaches and the potential for sudden hearing loss.
There are a number of reasons why people might turn to the internet for medication.
Aggressive advertising campaigns and stories on "wonder" weight loss pills in magazines can tempt people to bypass their GP or pharmacist.
We are even seeing unscrupulous operators preying on fears over swine flu, targeting the vulnerable and insecure with fake Tamiflu.
My advice to people thinking about ordering drugs online is simple - talk to your GP or pharmacist.
Your regular doctor knows you, your background and your health history, and what treatment is right for you.
Everybody is different.
I know that some issues can be embarrassing to talk about, but believe me, we have heard it all before.
Your GP is there to be non-judgmental, supportive and helpful.
Drugs and medication can achieve great results as long as they are prescribed and used properly.
Your health is far too important to play around with.