Dear Dr. Roach: As I amble past middle age and try to take note of my functioning as a male, I wonder if I could benefit from taking one of these testosterone supplements that I see advertised on TV. But I don’t know how much they would improve my health or sexual function. Does the recommended dosage on the bottle apply to everybody? Or should I ask me doctor to recommend me one? I am confused.

— R.G.

Answer: Unfortunately, the “testosterone supplements” you see in ads are misleading since they don’t contain testosterone. They are advertised to “support testosterone” and are made from vitamins (usually B vitamins), minerals (like magnesium and zinc), and a variety of supplements. One of these supplements is “horny goat weed,” which has estrogen-like characteristics and has never been proven to be effective for humans. It does contain a substance that works similarly to sildenafil (Viagra), but it is only about 1% as effective.

I absolutely recommend that you speak to your doctor. If the issue is erectile function, which does decrease with age in most men, then there are effective treatments that can be used once an evaluation is done looking for any possible cause. Causes can include low testosterone or a blockage in the artery to the penis.

Testosterone itself is a controlled substance that is appropriate for men with symptoms of low testosterone and who have repeatedly low blood levels of testosterone. If this includes you, then prescription testosterone and repeat blood tests are appropriate and should help your symptoms. I recommend that you stay away from these supplements.

Dear Dr. Roach: I live in a large apartment complex that still allows smoking, and some people here are extremely heavy smokers. Tenants must smoke in their units or in two designated areas that I avoid. Am I in danger of secondhand smoke?

I live in a wooded area two blocks away from the beach to enjoy fresh air, but the cigarette smell in my enclosed hallway is overwhelming at times. On many days, it can be smelled from the street outside the complex! Do I have a concern or just a super sensitive nose? I’ve never smoked.

— N.H.

Answer: The term “thirdhand smoke” is sometimes used to describe not the danger of smoking (firsthand), nor the danger of being around a person who is actively smoking (secondhand), but the residue of tobacco smoke left on surfaces and dust.

This residue can be found on the fingers of people who have moved into homes where smokers previously lived. There is even a little bit in the air as what has been left from smoking gets re-aerosolized. This is the biggest concern when people are living in a contaminated home. (Regular cleaning won’t get rid of all the residual chemicals from tobacco smoke.)

So, there is a concern, but the risk to your health, given that you are walking through a corridor, is small. Not touching the surfaces of the enclosed hallway is wise, and washing your hands when you come in is also a good idea. Some airflow from opening the windows in the corridor, if possible, would reduce the small risk.

Your nose may be sensitive, but what you are picking up is potentially harmful. From a long distance in the outside air, I suspect the risk is negligible.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.