1) Is it true that taking those Emergen-C packets or any other vitamin supplements can effect the effectiveness of your birth control pill?

2) I know antibiotics can lower the effectiveness of birth control, but can probiotics or prebiotics, such as a floral acidophilus FOS, also decrease effectiveness? I've been taking birth control pills for the past 10 years with no scares or baby bumps, and I don't want to wake up pregnant one day because I took a capsule that's supposed to be healthy! :)

My boyfriend claims he is HIV negative based on the fact that his blood donations have not been rejected. Is this a safe assumption? Is each and every pint of donated blood really tested for HIV and other blood-transmittable diseases? Do they really contact the donor if the blood is rejected because it tested positive for a blood-borne disease?

My best friend has AIDS and he's sexually active. He has unprotected sex with other men with HIV/AIDS. Should he use a condom instead or can does unprotected sex make no difference at all at this stage? Thank you.

First, I'd like to thank you for this service! It's been so informative to read the advice you've given others. I'm a female grad student and have just gotten into a relationship for the first time. I have a few questions regarding oral sex: my boyfriend loves to suck my nipples and I feel great when he's doing it, but after a while, my nipples start to feel tender and actually hurt sometimes... is this normal? He's not rough when he's doing it, so I'm not sure why this happens.

Also, when my boyfriend "goes down" on me, I worry about what he thinks of my smell and taste. He says he likes it, but I can't be sure... is there some way of finding out if my scent is normal? Can he pass any infections (to my vagina) from his saliva? (He has had only 1 one-night stand affair and he used a condom that time).

Also, I masturbate him (I stroke his penis) until he "comes," but I'm afraid of tasting his "come." He hasn't asked me to, but I think he would like it if I did... how can I overcome this inhibition? Are there any risks for me? I appreciate any help/advice... Thanks a lot!

1) Having read a few posts related to the question, "Is masturbation harmful?", most of the answers I've seen seem to suggest that the only possible harm could be psychological, in the sense that masturbation may be a distraction from one's normal routine.

What about the actual PHYSICAL side effects? Some things can not be dismissed as mere "wives' tales"! For example, when I masturbate often, I do notice a darkening under my eyes. I am only 28, but having been at this a while, it does seem as though I can not as easily become erect, or stay erect for as long as I used to. I may not have grown hair on my palms, but I have noticed (and I'm willing to concede that there may be no causal relationship here) that I have become somewhat hairier, in all the wrong places.

Please set the record straight as to what, if any, harmful PHYSICAL side effects may result from masturbation, and why, in the face of my testimonial and no doubt countless others, such symptoms as I have described are dismissed by yourself and your peers as "myths."

2) Does masturbation affect your growth if you are not yet fully grown?

I am 28 years old, and became sexually active two years ago. My husband is the only man I've ever had sex with, and I am his only sexual partner as well. Where does the gene or whatever it is that the HPV vaccine helps guard against come from? Because I'm too old to get the vaccine, are my chances of getting cervical cancer from this particular gene increased then? Thank you for your help.

I'm wondering if washing immediately and throughly after intercourse helps prevent pregnancy.