Nicotine skin patches are used to help the process of smoking cessation. They do not make up for a lack of willpower. If you have set your mind on stopping smoking, then patches are one of the ways in which you can cut down the worst of the withdrawal effects.

The skin acts as a good protection against the outside world, but anything we put on our skin can be absorbed to some extent. The pharmaceutical companies have used this fact and developed patches, which are like a small sticking plaster, which can contain drugs of various sorts (eg nicotine, hormones, sea sickness preparations).

When you take tablets of anything, the substance is absorbed from the gut and goes into the bloodstream, and the body slowly gets rid of it over the following hours. This results in fairly high levels of the drug in the blood shortly after taking the tablet, which drop down again until the next dose is taken. Patches, on the other hand, result in a much more constant amount of the substance being in the blood stream for the time the patch is attached.

As far as nicotine is concerned, this means that there is a constant but small amount in your bloodstream. This should help to overcome the worst of the physical withdrawal effects, but will not give the same effect or "buzz" as inhaling on your cigarette. The idea of this is that you will not in turn get addicted to the patches.

There are different strengths of patch. Heavy smokers need to start on the strongest strength, and work down to the lowest strength. Discuss this with your doctor or pharmacist.

As with most other drugs or medications, there are a large number of possible side effects, but in general terms you should be less likely to get side effects with these than you would if you continued smoking.

You should discuss the use of these with your doctor or pharmacist before starting to use them.

• Medinfo: Stop smoking