This section gathers articles on supplements studied for heart, circulation, and blood sugar concerns, with notes on what human studies show, doses used, and safety. This page lists all 9 ClinicalStudyConnect.com guides on the topic, each with its opening lines so you can pick the one that matches your question.
ClinicalStudyConnect.com is an independent publication. These guides are for education and do not replace care from a qualified professional.
Guides in this section
L-Arginine Benefits: What Human Studies Show, Doses, Safety
L-arginine is an amino acid studied for possible effects on blood pressure and other health outcomes. Human studies are small to moderate in size. They show a modest blood pressure drop in a handful of trials and possible benefit in pregnancy-related high blood pressure.
L-Citrulline Benefits: What Human Studies Show, Doses, Safety
L-citrulline is an amino acid your body makes on its own and that is also found in watermelon. Human studies point to a modest drop in blood pressure in middle-aged and older adults, a small and uncertain effect on exercise, and one small trial in mild erectile dysfunction.
Beet Root Benefits: What Human Studies Show, Doses and Safety
Beet root can give you a small boost in some exercise measures, and it lowered blood pressure in one small trial, but it has not been shown to treat or prevent any disease. It is the edible root of the beet plant, eaten whole or taken as juice, powder or extract, and it is rich in dietary nitrate.
Niacin Benefits: What Human Studies Show, Doses and Safety
Niacin (vitamin B3) is an essential nutrient, and most people in the United States already get more than they need from food.
Berberine Benefits: What Human Studies Show, Doses, Safety
Berberine is a compound found in plants such as goldenseal, barberry and Oregon grape. Human trials and reviews link it to modest drops in blood sugar and inflammation markers, but the studies are often low quality, so the findings are not firm.
Grape Seed Extract Benefits: What Human Studies Show
Grape seed extract is a supplement made from the seeds of wine grapes. Human studies are strongest for blood pressure and cholesterol, but the effects are small, results are mixed, and the studies are often small with products that differ from one to the next.
Apple Cider Vinegar: What Human Studies Show, Doses, Safety
Apple cider vinegar (ACV) is apple juice that has been fermented twice, and acetic acid is its main active ingredient, according to Cleveland Clinic . In human trials lasting 4 to 12 weeks, daily ACV was linked to small improvements in fasting blood sugar, body weight and total cholesterol.
Chromium Benefits, Side Effects and Doses: What Studies Show
Chromium is a trace mineral found in many foods and sold as a supplement, most often as chromium picolinate. Human trials have found small changes in blood sugar, body weight and some lab markers, but the changes are modest, the studies are often small or short, and several reviewers say they may not matter in practice.
Omega-3 Fatty Acid Clinical Trials: Evidence Across Health Outcomes and Study Quality
Omega-3 fatty acids, mainly EPA and DHA from fish oil and ALA from plant sources, have been tested in hundreds of registered clinical trials for heart health, triglyceride levels, brain function, pregnancy outcomes, and inflammation.