Lube and Sperm: Does Lubricant Affect Fertility?

Question
Hi Mr. Solberg,

My question is; can lube kill sperm? For example, my boyfriend and I always use condoms and have never had problems with leakage or anything. We used a little packet of lube too, and I think the tiniest amount may have gotten on the edge where we opened it. If we used it again several hours later, would the sperm still be active or would the chemicals kill them? It wasn't spermicidal lube.

Answer
Lube can kill and slow down sperm, but usually this effect is fairly minimal and no where near what a spermicidal jelly will do.  Condoms work well, but don't depend on lube to kill off many sperm.  If you want extra protection, use a spermicidal jelly with the condom.