Q: Recently, I came down with a sore throat and tried over-the-counter lozenges and sprays. They helped for a few minutes, but the pain quickly returned. An Asian friend told me to chew on a clove of garlic, so I did. It tasted awful, but the pain went away almost immediately.

My friend suggested chewing it with a little honey or olive oil to offset the flavor next time. Is there any research that shows why this works?

A: Garlic (Allium sativum) has been used medicinally for thousands of years. Cultures from China and India to Egypt and native North America have prized this bulb for its many healing properties.

Although there have been few scientific studies on its potential to ease cold symptoms or sore throat pain, researchers have identified antiviral and anti-inflammatory activity. For example, a study in the journal Viruses (April 25, 2023) demonstrates that allicin, an active ingredient in garlic, inhibits the virus responsible for a serious respiratory infection in pigs. It also calms cytokine production leading to inflammation. This might explain why your sore throat felt better after chewing on garlic.

There are some caveats, though. Some people find that raw garlic causes heartburn and stomach upset, not to mention bad breath.

Q: I have trouble sleeping more than two hours before having to get up to urinate every night. Is there a remedy? Melatonin pills don’t help, nor does soft music. Is there a patch that would help me sleep through the entire night?

A: Sleeping pills or patches may not solve your problem. Getting up every two hours to go to the bathroom suggests a medical condition called nocturia. This condition can be caused by several factors. You will need to consult a physician for a diagnosis.

One possibility is “nocturnal polyuria,” an overproduction of urine at night. A health care professional will also need to test for a urinary tract infection, diabetes, or heart or kidney problems. You may be asked to monitor urine output over 24 hours. If you are older than 65 and nighttime production is greater than 33% of your daily urine output, that could signal nocturnal polyuria.

One possible treatment is the drug desmopressin (Central European Journal of Urology, Nov. 2, 2020). When dissolved under the tongue an hour before bedtime, this hormone-like medication (Nocdurna) may be helpful. Your doctor will need to monitor your sodium levels and make sure your kidney function is normal.

Q: I’ve been treated for hypothyroidism for close to 40 years. After several years of trial and error along with a series of ultrasensitive TSH tests and avoiding certain foods, my thyroid hormone levels have stabilized. We no longer have to increase my dose of Synthroid on a regular basis.

My doctor suggested leaving a four-hour window before and after taking Synthroid when consuming calcium or soy. Otherwise, they might affect levothyroxine absorption. Lesser known are the effects of grapefruit and walnuts, which should be avoided. I take my pill when I get up during the night to go to the bathroom. This disrupts my sleep, but it means fewer problems with my diet.

A: You might be able to sleep better if you took your Synthroid pill at bedtime. Studies have shown that the results are similar to taking it first thing in the morning, half an hour before coffee and breakfast (Expert Review of Clinical Pharmacology, March 2024).

The only reference we could find to walnuts is very old (Endocrinology, March 1970). These researchers consider it a goitrogen, similar to cabbage, collards and broccoli. Excessive amounts of goitrogens interfere with thyroid hormone function.

In their column, Joe and Teresa Graedon answer letters from readers. Send questions to them via www.peoplespharmacy.com.