What are free radicals and antioxidants?

Just about everyone seems to be familiar with the terms antioxidants and free radicals. But most of us only recognise them as the ‘good guys’ and the ‘bad guys’. So let’s be brave and embrace a short lesson on free radical chemistry to gain a better understanding of the enemy we face on a daily basis.

Free radicals are very unstable. They vigorously search for an electron to complete their pair by stealing them from other molecules. When a molecule loses an electron to a free radical, it becomes a free radical itself and must now find an electron from another molecule to stabilise itself. It’s a vicious cycle that results in severe damage to skin cells as well as our stores of collagen and elastin. This is how free radical damage can induce premature skin ageing.


Fear not, we are not completely defenceless against free radical attack. On the contrary, we have a large selection of free radical fighting allies known as antioxidants.

Antioxidants are like the martyrs of skincare. They selflessly donate one of their own electrons to free radicals ending the electron-stealing cycle. Remarkably, antioxidants never become dangerous free radicals themselves. Their unique structure allows unpaired electrons to keep their stability without attacking other molecules. This helps to neutralise the damage caused by free radicals, preventing visible signs of ageing.

Our body has its own supply of antioxidants, but this can often be depleted by the sheer volume of pollution and UV-derived free radicals that we face on a daily basis. That’s why it is essential to keep your antioxidants topped up via your skincare.

Shop all Medik8’s full range of antioxidant serums here.



Search ingredients below to find out all about the ingredients we use and what they do.


As your body’s first line of defence against the environment, the skin is intricately designed...


With so many products, and only one face, where do you even start?


At Medik8, we truly understand skin.