Browse the evidence

Weekly subcutaneous semaglutide (up to 2.4 mg) significantly reduces liver steatosis and liver enzymes in patients with NAFLD/NASH, but does not significantly improve liver fibrosis or achieve NASH resolution compared to placebo in patients with compensated cirrhosis.

For patients with advanced liver disease (cirrhosis), weekly semaglutide injections (2.4 mg) can significantly reduce liver fat and inflammation markers, but they should not expect it to reverse scarring (fibrosis) or cure NASH. The treatment is safe and effective for metabolic control and steatosis reduction, even if it doesn't change the fibrosis stage.

Intentional weight loss in individuals with Type 2 Diabetes (T2D) is not consistently associated with reduced mortality risk and may be associated with higher mortality in obese subgroups, whereas weight cycling (body weight variability) is consistently associated with significantly increased all-cause and cardiovascular disease mortality.

If you have Type 2 Diabetes, do not focus on weight loss as a primary goal for reducing mortality risk. Instead, prioritize increasing physical activity and improving cardiorespiratory fitness. Weight cycling (losing and regaining weight) is associated with higher mortality risk, so maintaining a stable weight while improving fitness is a safer and more effective strategy for longevity.

Resistance training in humans and mechanical overload in rodents does not elevate muscle protein lactylation, challenging the hypothesis that lactate promotes skeletal muscle hypertrophy.

You do not need to maximize lactate accumulation (the 'burn') to trigger muscle protein lactylation or hypertrophy. Resistance training increases blood lactate significantly, but this does not translate to increased muscle protein lactylation or drive hypertrophy via this specific mechanism. Focus on mechanical overload rather than chasing lactate as a signaling molecule for growth.

Pharmacological treatment of prediabetes with anti-hyperglycemic drugs (e.g., metformin, TZDs, insulin) fails to provide long-term protection against diabetes because it does not correct underlying insulin resistance or beta-cell dysfunction, and benefits disappear upon discontinuation.

Standard diabetes drugs (like metformin) do not cure prediabetes. They mask high blood sugar while you take them, but once you stop, your risk of developing diabetes is the same as if you never took the drug. Focus on fixing the root cause (insulin resistance) rather than just lowering the number.

Preoperative use of GLP-1 receptor agonists does not improve long-term weight loss, diabetes remission, or surgical safety outcomes in patients undergoing metabolic bariatric surgery compared to those who do not use GLP-1s.

If you are considering bariatric surgery, using GLP-1 drugs (like Ozempic or Wegovy) beforehand does not appear to make your surgery more successful or your weight loss better in the long run. In fact, it may just delay getting the more effective surgical treatment. If you are experiencing side effects from these drugs or they aren't working well enough, switching to surgery is a valid and effective path, but don't expect the drugs to give you a 'head start' on your results.

Finerenone (a non-steroidal mineralocorticoid receptor antagonist) reduces hospital admissions for heart failure and end-stage kidney disease, and decreases mortality in Type 2 Diabetes patients with Chronic Kidney Disease (CKD).

If you have Type 2 Diabetes and Chronic Kidney Disease, ask about Finerenone. It is a non-steroidal medication that helps protect your heart and kidneys, reducing the risk of hospitalization for heart failure and kidney failure, though it requires monitoring for potassium levels.

Sustained administration of PYY(3-36) protects against high-fat diet-induced pancreatic and intestinal morphological deterioration by restoring ileal GLP-1 content and reducing beta-cell turnover.

This research suggests that maintaining healthy gut hormone levels, specifically GLP-1, is crucial for protecting pancreatic health during high-fat diets. While this study used direct PYY(3-36) injection, it supports the broader concept that enhancing incretin activity (like GLP-1) can protect pancreatic structure and function. For individuals, this underscores the importance of dietary patterns that support natural GLP-1 secretion and the potential therapeutic value of incretin-based interventions for metabolic health.

GLP-1 receptor agonists (GLP-1 RAs) are primarily prescribed as anti-diabetic medications (ADMs) rather than anti-obesity medications (AOMs), with 71.8% of first-time prescriptions designated for diabetes management and only 28.2% for obesity.

While GLP-1 medications like semaglutide and tirzepatide are famous for weight loss, the vast majority of prescriptions (over 70%) are for treating Type 2 Diabetes. If you are seeking these medications for weight loss, you may face higher costs and insurance hurdles because they are not primarily covered for obesity in many cases.

There is a significant disparity in medication initiation rates between diabetes and obesity indications, with 72.2% of diabetes prescriptions filled within 60 days compared to only 46.8% of obesity prescriptions.

If you are prescribed a GLP-1 for weight loss, be aware that you are less likely to fill the prescription than someone prescribed for diabetes. This is due to insurance coverage gaps, not a lack of desire to treat. Check your coverage status before the prescription is written to avoid delays.

Tirzepatide has surpassed semaglutide as the most commonly prescribed first-time GLP-1 RA medication in the US as of September 2025.

Tirzepatide is now the most frequently prescribed first-time GLP-1 medication in the US, overtaking semaglutide. This reflects changing prescribing preferences among physicians.

Intermittent diet breaks (one week of energy balance every two weeks) during a 25% energy deficit do not improve body composition or resting metabolic rate compared to continuous energy restriction in resistance-trained females.

If you are a resistance-trained woman, taking one-week diet breaks every two weeks during a 25% calorie deficit will not help you lose fat or preserve muscle any better than dieting continuously for the same total time in deficit. You can use breaks if you psychologically need them, but do not expect them to save your metabolism or muscle mass compared to sticking to the deficit continuously.

Downregulation of the transcription factor NR4A3 in human skeletal muscle, mimicking physical inactivity, impairs glucose oxidation and protein synthesis while increasing fatty acid oxidation and lactate production, leading to muscle atrophy.

Physical inactivity actively suppresses a key protein (NR4A3) in your muscles, which shifts your metabolism away from burning glucose and toward making lactate, while simultaneously shutting down muscle building signals. This molecular change is a primary driver of muscle loss during sedentary periods. While this study was done on cells, it suggests that maintaining NR4A3 levels (e.g., through movement) is crucial for preserving muscle mass and metabolic health, and future therapies might target this pathway.

Dual GLP1R/GIPR agonists achieve superior glucose lowering and weight reduction compared to single GLP1R agonists through specific engagement of pancreatic islet cells (beta, alpha, delta) and circumventricular organ neurons, rather than through enhanced brain penetration.

Dual GLP1/GIP agonists work better than single GLP1 drugs because they target specific cells in the pancreas (beta, alpha, delta) and specific neurons in the brain's edge (circumventricular organs), not because they penetrate the brain deeper. This targeted engagement drives superior glucose and weight outcomes.

Dual GLP1R/GIPR agonists label pancreatic beta, alpha, and delta cells with varying intensity (beta > alpha = delta), engaging distinct receptor nanodomains that differ from those targeted by single agonists.

Dual agonists affect multiple hormone-secreting cells in the pancreas, with the strongest effect on insulin-secreting beta cells, followed by glucagon-secreting alpha and somatostatin-secreting delta cells.

A specific missense variant in the GIP receptor (GIPR, rs1800437, p.Glu354Gln) is associated with an increased risk of vomiting in patients treated with tirzepatide, but not semaglutide.

If you are taking tirzepatide (Mounjaro/Zepbound), your genetics can influence your risk of vomiting. A specific variant in the GIP receptor (rs1800437) is linked to a higher risk of vomiting. This is specific to tirzepatide because it targets both GLP-1 and GIP receptors. If you experience severe vomiting, discussing your genetic history or considering alternative therapies might be beneficial, as this genetic factor does not affect semaglutide users.

Recent safety data from the SELECT trial indicates a higher incidence of hip and pelvic fractures in female patients and those aged 75+ taking semaglutide 2.4 mg weekly compared to placebo.

If you are over 75 or a postmenopausal woman taking semaglutide for heart health, be aware that your risk of hip or pelvic fractures may be slightly higher than if you were not taking the drug. This risk is likely linked to the weight and muscle loss. Ensure you are doing strength training, getting enough calcium/Vitamin D, and discussing bone density scans (DEXA) with your doctor.

Setmelanotide, a melanocortin-4 receptor (MC4R) agonist, produces significant weight loss in patients with specific genetic obesity disorders (POMC, LEPR, or PCSK1 deficiency).

Setmelanotide is an FDA-approved treatment for obesity caused by specific genetic mutations (POMC, LEPR, or PCSK1 deficiency). In clinical trials, it led to significant weight loss (up to 51 kg over 42 weeks) in patients with these conditions. It is not for general obesity but targets the underlying hormonal pathway affected by these genetic disorders.

Pharmacologic activation of GIP and GLP-1 receptors rapidly inhibits AgRP neurons, and this neural inhibition contributes to the appetite-suppressing effects of incretin-based obesity therapies.

Incretin-based medications (like semaglutide and tirzepatide) work in part by shutting down hunger-promoting brain cells (AgRP neurons). This mechanism is driven by both GIP and GLP-1 pathways, with dual-action drugs being more effective than single-action ones. This neural inhibition helps explain why these drugs successfully reduce food intake, even in individuals with obesity.

Genetically modeled dual GIPR/GLP1R agonism reduces binge drinking frequency and the risk of heavy drinking with psychiatric comorbidities.

Genetic evidence suggests that activating GLP-1 and GIP receptors (via drugs like semaglutide or tirzepatide) can reduce binge drinking and heavy drinking, especially in those with psychiatric comorbidities. This effect appears independent of general alcohol consumption (drinks per week), suggesting a specific impact on high-risk drinking patterns.

In adults with type 2 diabetes, behavioral weight loss interventions do not significantly reduce the long-term risk of cardiovascular disease events or all-cause mortality compared to standard care.

For people with type 2 diabetes, relying solely on behavioral weight loss interventions (diet and exercise) may not be enough to prevent cardiovascular disease or death in the long term. While weight loss is still recommended for other benefits like diabetes remission, patients should discuss comprehensive cardiovascular risk management, including medications with proven cardiovascular benefits, with their healthcare provider.

Higher adiposity (BMI) is positively associated with increased striatal dopamine tone in humans, as indicated by the differential displacement of low-affinity D2 receptor tracers.

This research suggests that higher body weight is associated with higher baseline (tonic) dopamine levels in the brain's reward centers. This may alter how rewarding food feels, potentially contributing to overeating. While this doesn't provide a direct 'fix,' it highlights that obesity is a neurochemical state, not just a willpower failure. Interventions might need to account for this altered reward sensitivity.

High out-of-pocket costs for semaglutide create a socioeconomic barrier to access, resulting in significantly lower prescription rates among low-income individuals despite them having a higher prevalence of obesity.

If you are on a limited budget, the high out-of-pocket cost of semaglutide may prevent you from accessing it, even if you have obesity. This is a systemic issue where low-income individuals are undertreated. Advocacy for reimbursement or subsidies is needed to address this inequality.

Lean individuals with Metabolic Dysfunction-Associated Fatty Liver Disease (lean-MAFLD) face a significantly higher risk of liver-related mortality compared to overweight or obese MAFLD patients, despite having equivalent metabolic profiles and similar risks for extrahepatic mortality.

If you are lean but have been diagnosed with fatty liver (MAFLD), do not assume you are safe because you are thin. Your risk of liver-related death is actually higher than that of obese patients with the same condition. Standard weight loss advice, especially rapid loss via drugs, can be dangerous for you because it strips away muscle, which your liver needs. Focus on metabolic health markers (blood pressure, glucose, lipids) and consult your doctor about treatments that preserve muscle mass rather than just focusing on weight loss.

Co-ingesting cluster dextrin (CDX) with protein after resistance exercise does not increase myofibrillar protein synthesis or total amino acid availability compared to glucose, despite enhancing intramuscular mTORC1 signaling.

If you are eating protein after resistance training, switching from glucose to cluster dextrin will not help you build more muscle. While CDX might trigger slightly higher signaling markers (mTORC1), it does not translate to actual muscle protein synthesis gains compared to regular glucose. Stick to what works and costs less.