Use of a lubricant when having sex can do all of the following:
- Make sexual penetration more comfortable.
- Help reduce the risk of condom breakage.
- Reduce the risk of tearing membrane inside the vagina or rectum, opening the recipient to transmission of the HIV virus to the recipient's blood stream.
All lubricants are not created equal for these purposes. In fact, only water based lubricants should be used. Oil based lubricants such as baby oil or Vaseline can break a condom.
When nonoxynol-9 (N-9) was first introduced, it was believed that it would kill the HIV virus. However, according to San Francisco AIDS Foundation: "… it's been documented that N-9 Current studies show that instead that N-9 washes away the protective cells and might actually increase the risk of infection. Due to public pressure, all lubricant manufacturers agreed to stop making lube with nonoxynol-9. There are, however, manufacturers that continue to make condoms laced with N-0. Condoms containing N-9 should not be used for anal sex; however, if a condom containing N-9 is the only method available, using this condom is significantly safer than using no condom at all."