Women who've missed several periods and wonder whether they're nearing menopause now can turn to an at-home test -- but the results may not be as conclusive as a visit to their doctor.

The Food and Drug Administration has approved Menocheck as the first retail home test to measure the level of follicle-stimulating hormone (FSH), whose levels rise as a woman's body approaches the cessation of fertility.

The test works like a pregnancy test: A woman checks her urine first thing in the morning using the absorbent tip of a special wand that also has an indicator panel. After five minutes, she should see a positive or negative result for high levels of the hormone. She repeats the test five to seven days later.

Two positive readings in a row suggest a woman is either in late perimenopause or has reached menopause (12 months without a full menstrual cycle), said Dr. Laura Corio, a menopause specialist who serves as a product spokeswoman.

But some doctors who treat menopause say such tests could create more anxiety than they alleviate, and keep some women away from proper care.

"It's going to lead to nothing but confusion," said Dr. Wulf Utian, executive director of the North American Menopause Society. FSH levels typically fluctuate for six or seven years so women could get a couple of positive Menocheck readings without having reached menopause. They could also be stumped by one positive and one negative reading.

"If you're 45 to 55 and are missing periods and have irregular cycles, that's the message to go along and get yourself the appropriate checkup," said Utian. "Even if you don't have an elevated FSH and are missing periods, it's worth seeing the doctor."

Doctors can discuss with patients how they can prevent osteoporosis and cardiovascular disease, which are both associated with declines in estrogen.

The $19.99 test kit from Synova Healthcare Inc. of Media, Pa., contains two single-use tests. It's available through Walgreens, but will be sold by other stores in mid-January.