A friend of mine said that the only birth control she uses is the morning-after pill. Is that safe?

— J.Y., New York

I’m curious to know if she’s taking Plan B or RU-486. Plan B is available over the counter with no prescription. It prevents pregnancy by flooding a woman’s body with a mega dose of progesterone. It works by either preventing or delaying ovulation and may interfere with the fertilization of the egg. It’s nowhere near as good as condoms or regular birth control pills in preventing pregnancy, and is between 15 and 25 percent less effective.

Plan B has been described as safe and harmless with mild side effects, but there’s no way pumping a megadose of hormones into your body is good for you. The internet is full of women writing on message boards and blogs about how after taking Plan B just once they experienced sharp abdominal pain, vomiting, weight gain, mood swings, changes to their periods and their sex drive — and that’s just from taking the pill once, not the multiple times your friend has taken it.

Unlike Plan B, which prevents fertilization by changing your ovulation cycle, RU-486, also referred to as the abortion pill, causes the uterus to empty, which is a nice way of saying it chemically induces a miscarriage. About 99 percent of the women who use RU-486 experience at least one of the following symptoms: abdominal pain, nausea, headache, vomiting, diarrhea, dizziness, fatigue, back pain, uterine bleeding, fever, viral infections, vaginitis and/or rigors (chills and shaking). RU-486 is no joke and shouldn’t be taken casually as a preventive measure. Seven percent of women who take it experience uterine hemorrhaging. Septic shock and death are not unheard of. This drug is so invasive and has so many side effects that it’s been banned in China.

I suggest getting your friend to Planned Parenthood and having her start taking daily birth control and using condoms. Taking a daily pill is much easier, healthier and safer than whatever post-coital birth control method she’s attempting.

And don’t forget condoms, because there’s all sorts of shit you can get from sex aside from babies. You know about the big names like HIV, herpes and chlamydia, but a bunch of other weird stuff can happen to your junk if you don’t wrap it up. Do you know what trichomoniasis is? It’s profoundly uncomfortable, men are asymptomatic and there’s no test for them. Gross.

So wear a condom to keep your coochy clean and baby-free. If you won’t do it for yourself, do it for the nation. In 2010, the Centers for Disease Control and Prevention estimated that there are 19 million new STDs every year. Herpes is for life and the medication to manage the symptoms is expensive. HIV will kill you. If your friend’s only worried about pregnancy, she’s missing the bigger picture.

This column doesn’t constitute medical or professional advice. Always consult a qualified health care professional for your medical, psychological, or relationship problems.