Do you use personal lubricants? If the answer is “yes,” you might want to read the following article about why most sexual lubricants are not safe for your body. They can damage the cell lining in the vagina or rectum increasing the risks of infectious disease transmission.
So why are these lubricants allowed to be sold? Like other parts of the adult industry, lubes are not regulated (in the US) as strongly as other products that we use on a daily basis. So that means that manufacturers can put as much chemicals (mostly glycerin and propylene glycol) they want into the lubricant.
The moral of the story is that if you have many sexual partners and use lube, please be careful. You might be more susceptible to catching something. I would recommend an all-natural or organic lubricant that closely matches the body’s natural lubrication.