8-hydroxy-2-deoxyguanosine (8-OHdG) is a marker of cell damage caused by oxidative stress. Our cells have protective mechanisms to minimize damage, but sometimes the balance is upset, and 8-OHdG is produced. High levels of 8-OHdG reflect high oxidative stress. If the levels are very high, medication such as Metformin or rapamycin may be used to remove damaged cells. To lower high 8-OHdG levels, consider taking supplements such as Vitamin C, E, lipoic acid, and NAC, and consuming EGCG and green tea, spermidine.