Can medication change your DNA?

Answered by Marianne Baker, Barts Cancer Institute.

Most drugs act on proteins - the molecules in our cells that do particular jobs - so they don't change your underlying DNA. But some can act on DNA - for example many chemotherapy drugs, such as cisplatin, damage DNA and make cancer cells die. But they can also damage DNA in healthy cells too, causing side effects. Some other new cancer drugs in development are designed to change the molecular 'tags' on your DNA, known as methylation and acetylation, affecting how genes are switched on or off. While DNA-altering drugs will usually just kill cells in your body rather than just causing long-term changes, there are more serious consequences if women take them while pregnant. The controversial drug thalidomide can also affect DNA, causing birth defects if it's taken by pregnant women, and there are other examples of drugs that can also have this effect and must be avoided in pregnancy.