Browse the evidence

Metformin is the preferred first-line pharmacological monotherapy for type 2 diabetes, to be continued unless contraindicated.

If lifestyle changes alone don't control your blood sugar, metformin is the standard first medication. It is generally well-tolerated and effective. Take it as prescribed unless you have specific health reasons that prevent its use.

Vitamin D supplementation at typical doses (400–8571 IU/d) does not produce clinically significant improvements in blood pressure, glycemic control, or cardiovascular disease risk in generally healthy adults.

Taking Vitamin D supplements (even at high doses up to 8571 IU/day) will not lower your blood pressure, prevent diabetes, or protect your heart if you are already generally healthy. Do not rely on Vitamin D as a substitute for proven lifestyle changes or medications for these conditions.

Antihistaminergic drugs, antipsychotics, fast-release melatonin, ramelteon, and phytotherapeutics are not recommended for insomnia treatment.

Avoid using antihistamines, antipsychotics, fast-release melatonin, ramelteon, or herbal supplements for treating insomnia, as they are not recommended by current guidelines.

Daily supplementation with 1 gram of n-3 fatty acids (460 mg EPA and 380 mg DHA) does not significantly reduce the risk of serious vascular events in patients with diabetes mellitus without established cardiovascular disease.

If you have diabetes but no known heart disease, taking 1 gram of fish oil daily (providing 460mg EPA and 380mg DHA) will not significantly lower your risk of heart attacks, strokes, or vascular death compared to taking a placebo. This large, long-term study suggests that routine supplementation with these specific doses is not an effective strategy for preventing cardiovascular events in this group.

SGLT-2 inhibitors and GLP-1 receptor agonists reduce all-cause mortality, cardiovascular mortality, non-fatal myocardial infarction, and kidney failure in patients with type 2 diabetes, with absolute benefits scaling with baseline cardiovascular and renal risk.

If you have type 2 diabetes, especially with existing heart or kidney risks, adding an SGLT-2 inhibitor or GLP-1 agonist to your current regimen significantly reduces your risk of dying from heart or kidney causes. The higher your baseline risk, the greater the absolute benefit. Discuss these specific drug classes with your doctor to leverage these organ-protective effects.

SGLT-2 inhibitors are superior to GLP-1 receptor agonists for reducing hospital admissions for heart failure, while GLP-1 receptor agonists are superior for reducing non-fatal stroke.

Choose your diabetes drug based on your specific health history, not just blood sugar. If you have heart failure, an SGLT-2 inhibitor offers superior protection. If you have a history of stroke, a GLP-1 agonist is likely the better option. Ask your doctor which class aligns with your specific risks.

Circadian misalignment between endogenous rhythms and exogenous sleep schedules causes Shift Work Disorder (SWD) and Jet Lag Disorder (JLD), characterized by sleep disturbance and impairment.

If you suffer from shift work or jet lag, the root cause is likely a mismatch between your internal body clock and your external schedule. Diagnosis requires documenting this misalignment, often using sleep logs or actigraphy for at least seven days. Treatment focuses on realigning the clock through scheduled sleep, timed light exposure, or melatonin.

Dim Light Melatonin Onset (DLMO) is a more stable and accurate marker of circadian phase than Core Body Temperature (CBT) because it is less susceptible to masking effects.

For accurate diagnosis of circadian disorders, measuring the Dim Light Melatonin Onset (DLMO) is superior to using Core Body Temperature. DLMO is less affected by daily activities and provides a more stable marker of your internal clock's phase, facilitating more precise treatment planning.

A Mediterranean diet supplemented with mixed nuts reduces diabetes risk, but the effect is not statistically significant compared to a low-fat control diet in this specific analysis.

Adding 30 grams of mixed nuts daily to a Mediterranean diet may help lower diabetes risk, but the evidence for this specific combination is less conclusive than for olive oil. It is still a healthy addition, but do not rely on it as the sole preventive strategy if you are at high risk.

Polysomnography (PSG) is not routinely indicated for the diagnosis of Circadian Rhythm Sleep Disorders (CRSDs) but is indicated to rule out other primary sleep disorders.

Do not expect a sleep lab test (PSG) to diagnose your circadian disorder. Instead, track your sleep with logs or actigraphy. PSG is only used if your doctor suspects another condition like sleep apnea.

Monthly high-dose vitamin D3 supplementation (200,000 IU initial, then 100,000 IU monthly) does not prevent cardiovascular disease in the general population.

Taking 100,000 IU of Vitamin D3 once a month will not prevent heart disease or stroke, even if you are deficient. While maintaining adequate Vitamin D levels is important for bone health, this specific high-dose monthly regimen has not been shown to reduce cardiovascular risk in older adults. Do not use Vitamin D as a substitute for standard cardiovascular prevention strategies.

Ultrasound (US) is the preferred first-line diagnostic procedure for imaging NAFLD due to its availability and cost-effectiveness, despite lower sensitivity for mild steatosis compared to MRI.

If you have risk factors for NAFLD (obesity, diabetes), ask your doctor for an abdominal ultrasound. It is the standard, accessible way to check for liver fat.

Cardiovascular disease (CVD) is the leading cause of death in NAFLD patients, making cardiovascular screening mandatory regardless of traditional risk factors.

If you have NAFLD, prioritize your heart health. Get regular cardiovascular screenings (blood pressure, cholesterol) as strictly as you monitor your liver.

Resmetirom is a recommended pharmacotherapy for adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2), demonstrating histological effectiveness on steatohepatitis and fibrosis.

If you have advanced liver scarring (fibrosis stage 2 or higher) but not cirrhosis, ask your doctor about resmetirom, a medication that can improve liver health.

Bariatric surgery is an option for individuals with MASLD and obesity.

If you have obesity and MASLD, discuss bariatric surgery with your doctor as a potential option to improve your liver health.

There is no evidence that lifestyle interventions improve live birth, miscarriage rates, or menstrual regularity in women with PCOS.

Current evidence does not show that lifestyle changes improve menstrual regularity or fertility (live birth) in women with PCOS. While weight loss is beneficial, it should not be relied upon to restore regular cycles or ensure pregnancy.

Maxillomandibular advancement (MMA) is indicated for severe obstructive sleep apnea (OSA) in patients who cannot tolerate or are unwilling to adhere to positive airway pressure (PAP) therapy, or in whom oral appliances have failed.

If you have severe sleep apnea and cannot use your CPAP machine or dental devices, jaw surgery (MMA) is a valid option to discuss with your surgeon. It physically moves your jaw forward to keep your airway open. While the evidence quality is low, it often significantly reduces breathing pauses. It is not a first choice, but a necessary backup for severe cases.

Uvulopalatopharyngoplasty (UPPP) as a sole procedure does not reliably normalize the Apnea-Hypopnea Index (AHI) in patients with moderate to severe OSA.

If you have moderate or severe sleep apnea, removing your uvula and tonsils (UPPP) alone is unlikely to cure your condition. Studies show breathing pauses often remain severe after this surgery. You should prioritize CPAP or oral appliances first, as they are more reliable.

Radiofrequency ablation (RFA) and palatal implants are acceptable options for mild to moderate OSA in patients who cannot tolerate or adhere to PAP therapy or oral appliances.

If you have mild or moderate sleep apnea and can't use CPAP or dental devices, radiofrequency ablation or palatal implants might help reduce your symptoms. However, they are not cures; you will likely still have some breathing pauses. Follow-up is essential to monitor your progress.

Replacing saturated fat with linoleic acid-rich vegetable oils lowers serum cholesterol but does not reduce mortality from coronary heart disease or all-cause mortality, and may be associated with higher risk of death in those with greater cholesterol reductions.

Current dietary guidelines recommending the replacement of saturated fats with linoleic acid-rich vegetable oils (like corn or soybean oil) to lower cholesterol do not appear to reduce the risk of death from heart disease or all causes. In fact, this specific large-scale trial suggests that achieving lower cholesterol through this method might be associated with a higher risk of death. Individuals should be aware that lowering cholesterol via this specific dietary swap may not confer the expected survival benefit.

Testosterone therapy is not recommended for healthy women or those with conditions other than hypoactive sexual desire disorder (HSDD) due to lack of defined syndrome, unclear correlation between levels and symptoms, and insufficient long-term safety data.

Do not seek testosterone therapy for general fatigue, low libido, or 'anti-aging' unless you have been specifically diagnosed with HSDD by a specialist. There is no established 'low T syndrome' in women, and treating based on blood levels alone is not supported by evidence and carries unknown long-term risks.

Dehydroepiandrosterone (DHEA) is not recommended for general use in women due to inadequate indications and lack of evidence for efficacy and long-term safety.

Do not use DHEA supplements for general health, bone density, or cognitive enhancement. There is insufficient evidence to support its efficacy or long-term safety in women.

There is no clear evidence that portion, package, or tableware size affects the selection or consumption of alcohol or tobacco products.

Changing the size of alcohol or tobacco packages is unlikely to have a significant impact on consumption based on current evidence.

Bariatric surgery is the most effective treatment for morbid obesity, providing substantial long-term mortality reduction and remission of type 2 diabetes (T2DM) compared to non-surgical management.

For individuals with severe obesity (BMI ≥40 or ≥35 with comorbidities) who have not succeeded with lifestyle changes, bariatric surgery is the most effective medical intervention for long-term survival and diabetes remission. It is not a quick fix but a lifelong commitment requiring strict adherence to nutritional supplementation and medical monitoring to prevent deficiencies and manage metabolic health.