How they work: Kits such as CholesTrak or Home Access (both under $15 per test) use a drop of your blood to determine your total cholesterol level. CardioChek (over $100) also measures high-density lipoprotein ("good") cholesterol and triglycerides (bad fat in your blood). With these numbers, you can estimate low-density lipoprotein ("bad") cholesterol.
What the experts say: The more affordable tests don't provide enough information to be useful. "You really need to know the breakdown of the different types of cholesterol to accurately assess your heart risk," says Stanley L. Hazen, M.D., Ph.D., head of preventive cardiology and cardiac rehabilitation at the Cleveland Clinic Foundation. And CardioChek, which does give more precise information, can be tricky to perform correctly — and a misstep can mean unreliable results. What's more, healthy adults under age 50 need cholesterol tests only every five years, says Hazen. He recommends relying on a lab test, and then reviewing the results with your doctor.
His-and-her fertility screening
How they work: The Fertell Couples Fertility Test ($99) includes both male and female fertility tests. Your guy produces a semen sample into a collection container, which measures the concentration of "motile" sperm — a marker of sperm health. You pee onto a testing stick on the third day of your period to reveal your levels of follicle-stimulating hormone (FSH), an indicator of your ability to produce viable eggs.
What the experts say: Infertility is a complex problem that isn't amenable to quick analysis, says Lee P. Shulman, M.D., a professor of ob/gyn at the Northwestern University Fineberg School of Medicine in Chicago. For example, shape, size, volume, and speed are equally important factors in sperm health. And a single check of FSH doesn't reliably tell you whether you have a healthy egg supply. If your results are normal, you may be lulled into false assurance. And if the test indicates trouble, the results would need to be double-checked by a doctor. "This just adds one more costly step to the expensive process of infertility testing," says Shulman.
Vaginal yeast infection tests
How they work: You either wear a panty liner that has an embedded test strip (Fem-V, $8) or briefly insert a wand into your vagina (Vagisil Screening Kit, $8.50). Both tests work by measuring the pH of your vaginal discharge: If levels are in the normal range, your symptoms of vaginal itching and abnormal discharge may signal a yeast infection, which can be safely treated with an over-the-counter medication, such as Monistat. If pH levels are elevated, symptoms may be due to bacterial vaginosis or parasitic infection, which can lead to infertility if left untreated.
What the experts say: "Everything that itches is not a yeast infection, and these products can help determine what your problem is," says Jill Maura Rabin, M.D., an associate professor of ob/gyn at Albert Einstein College of Medicine in Bronx, NY.
Urinary tract infection (UTI) tests
How they work: You pee onto a test strip that tells you if your urine contains nitrates, protein, and/or white blood cells. If it does, your symptoms of burning during urination may indicate a UTI. Kits such as AZO Test Strips and Consumers Choice Systems UTI Home Screening Test cost about $10.
What the experts say: You could use a test to confirm an infection, then call your doctor, who might be willing to call in a prescription remedy, says Rabin. "But if you also have back pain, chills, or a fever, it could be a kidney infection, which can lead to permanent kidney damage, so head straight to the doctor."