Q&A: Why Dry January and GLP-1 Therapy May Be a Turning Point for Metabolic Health

In an interview with Pharmacy Times, David Shusterman, MD, chief executive officer at Modern Urologist in New York City, discussed how alcohol metabolism disrupts glucose regulation, increases insulin resistance, and accelerates kidney damage.

Shusterman explained how glucagon-like peptide-1 (GLP-1) medications regulate insulin, reduce sugar spikes, and protect kidney function, particularly in metabolically at-risk men. Reducing or eliminating alcohol improves GLP-1 effectiveness, tolerance, and overall metabolic outcomes, especially during early treatment. Combining GLP-1 therapy with alcohol reduction, such as Dry January, can improve sleep, mood, weight management, and long-term kidney health.

Pharmacy Times: Can you introduce yourself and explain your current role?

David Shusterman, MD: I'm David Shusterman. I'm a urologist at Modern Urologist—it’s my practice in New York City. We focus on high-tech, minimally invasive, longevity-preserving techniques that concentrate on established medical care and established medicine. I was one of the first people in New York to start using GLP-1s for weight control. I found them to be invaluable. I was the first one to use it on myself just to make sure that it works, and I could tell you it worked very well. I'm very happy with it, and I'm still on it 4 or 5 years later.

Pharmacy Times: Can you explain how alcohol is metabolized like sugar and why this process stresses the kidneys and raises insulin demand?

Shusterman: Well, interestingly, it's a kind of secondary effect on the kidneys. The primary effect is obviously on the liver. Most people know that alcohol is processed in the liver, and it takes priority over other processes in the liver. The main reason is because alcohol is a toxin, so your body prioritizes toxins over glucose, which is a normal byproduct of eating and one of our primary fuel sources.

When the liver prioritizes alcohol, it halts the production of glycogen neogenesis. Glycogen is the storage form of glucose. When production stops, it spikes levels of glucose, which spikes insulin levels, and it also has direct effects on muscles and other organs. Alcohol reduces insulin sensitivity in other organs, and by spiking glucose levels, you're actually hurting your kidneys because kidneys are very sensitive to high levels of glucose.

Pharmacy Times: How does excess sugar and insulin resistance contribute to kidney overload, and why does alcohol accelerate this cycle?

Shusterman: When you have excess sugar, especially with alcohol, the primary mechanism of how your body handles it is by secreting insulin. Insulin lowers sugar by absorbing it into tissue and the liver and has many effects throughout the body. If alcohol blunts this effect, it worsens insulin resistance.

When there's insulin resistance, you then have higher levels of sugar, which is diabetes. Studies indicate that heavy alcohol use increases blood sugar by a factor of two. The liver works very hard processing alcohol, which causes inflammation. Blood sugar spikes then reach the kidney glomeruli, blocking filtration units and causing kidney inflammation, which worsens kidney function and affects blood vessels, nerves, and other organs throughout the body.

Pharmacy Times: How do GLP-1 medications help regulate insulin, reduce sugar spikes, and protect kidney function, especially in men at metabolic risk?

Shusterman: GLP-1 is such a great medication because it mimics gut hormones. These hormones prevent low blood sugar from happening. By slowing gastric emptying, it increases hormones that tell you you're full and that glucose is entering your body. This helps remove glucose and signals fullness to the brain more quickly.

It protects the kidneys by reducing inflammation, improving blood flow, and lowering proteinuria by about 20% to 30%, slowing chronic kidney disease. GLP-1s were originally diabetic medications, and after starting them, eating decreased significantly. Lower food intake, weight loss, and lower blood sugar reduce inflammation, improve kidney blood flow, and prevent the harmful effects of diabetes. GLP-1s are a game changer for anyone with metabolic risk, particularly those with significant belly fat.

Pharmacy Times: Why does reducing or eliminating alcohol make GLP-1 therapy safer and more effective, particularly during the first month of treatment?

Shusterman: During the first month of treatment, we use a very low dose while the body acclimates to GLP-1. I found that many people stop GLP-1 because alcohol counteracts its effects. GLP-1 reduces blood glucose, while alcohol increases it, which blunts its effectiveness and can cause toxic issues.

Alcohol has empty calories, contributes to vomiting, and worsens tolerance. I advise patients to eliminate alcohol as much as possible or reduce intake by diluting drinks or cutting portions in half. Studies show quitting alcohol improves GLP-1 effectiveness by about 30% to 36%. GLP-1s also reduce alcohol cravings, and increased GLP-1 use has correlated with decreased alcohol consumption.

Pharmacy Times: What early signs of kidney stress do men often overlook, and why is Dry January an ideal time to address them?

Shusterman: January is a good time, especially on GLP-1, to stop alcohol. Cravings decrease significantly, and drinking often remains lower even after Dry January. Overlooked signs include fatigue, urination changes, ankle swelling, skin itching, metallic taste, hair loss, and appearance changes that are often attributed to aging or dehydration.

In men, muscle mass can mask rising creatinine levels. Creatinine increases from one to two indicate about half of normal kidney function remaining. Because symptoms are minimal early on, this is the best window to intervene.

Pharmacy Times: How can combining Dry January with GLP-1 therapy improve sleep, mood, weight management, and urinary health simultaneously?

Shusterman: Stopping alcohol improves sleep by reducing REM disruption. Alcohol is a diuretic and causes dehydration, which damages kidneys. Weight loss from GLP-1 improves sleep apnea and sleep quality.

GLP-1 has anti-inflammatory effects, while alcohol contributes to depression and anxiety. Weight loss improves mood, confidence, and social feedback. Lower glucose levels, reduced dehydration, and fewer hangover effects reduce kidney stress and improve urinary health, making this a powerful reset.

Pharmacy Times: Is there anything you would like to add?

Shusterman: Many people hear negative reports about GLP-1s, but when you look at how many benefits they have, lowering body weight reduces diabetes risk and significantly improves longevity. There are isolated cases where GLP-1s are not tolerated, and those should be discontinued early.

GLP-1s remain an important medicine in our arsenal and will continue growing in popularity. Like antibiotics, benefits outweigh isolated adverse effects. I have not been paid by any companies to say this; these observations come from my own experience and my patients, and the positive effects far outweigh the negatives.