High Blood Pressure

Often called the "silent killer," hypertension causes no symptoms for decades while progressively damaging the heart, kidneys, brain and arteries. It affects about 1 in 3 adults globally. Diet and lifestyle change lower blood pressure meaningfully and are first-line in every major guideline, but most people with established hypertension also need medication, and the two work together rather than as alternatives.

Cardiovascular & Metabolic Evidence-Based

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โš ๏ธ Medication safety: please read first. The nutrition and supplement approaches on this page are meant to work alongside your prescribed treatment, never to replace it. Never stop, reduce or change your blood-pressure medication without your prescriber's guidance. Doing so can be dangerous. Several supplements interact with blood-pressure medication, so talk to your prescriber or pharmacist before starting anything on this page.

What Is High Blood Pressure?

High blood pressure (hypertension) is defined as a consistently elevated blood pressure โ‰ฅ130/80 mmHg (2017 ACC/AHA guideline) or โ‰ฅ140/90 mmHg (WHO and European guidelines). It represents the sustained state of excess mechanical force on arterial walls, a force that silently erodes cardiovascular health over years.

The heart pumps blood against resistance provided by the arteries. When arterial stiffness increases (from inflammation, plaque buildup or endothelial damage), the heart must pump harder. This creates a vicious cycle: high pressure accelerates arterial damage, which raises resistance further, which raises pressure more.

Most hypertension is "primary" or "essential," meaning there is no single identifiable cause: the risk builds from age, family history, a diet too high in sodium and too low in potassium, excess weight, physical inactivity, tobacco use and too much alcohol, acting together over years20.

โš ๏ธ Hypertension usually causes no symptoms until a serious event (heart attack, stroke, kidney failure). The only way to know is to measure it regularly; guidelines treat 130/80 mmHg and above as high, and below 120/80 as normal.
A torso with the heart and its arteries and veins, a blood pressure cuff on the arm with arrows labeled systolic and diastolic, and a close-up of red blood cells in a vessel

Blood Pressure Stages

โœ… Normal

<120/80

Optimal cardiovascular risk

โšก Elevated

120 to 129 / <80

Intervene now with lifestyle

โš ๏ธ Stage 1 Hypertension

130 to 139 / 80 to 89

Lifestyle + possible medication

๐Ÿšจ Stage 2 Hypertension

โ‰ฅ140 / โ‰ฅ90

Medication typically required

High Blood Pressure by the Numbers

1.4B
adults aged 30 to 79 worldwide have hypertension, about a third of that age group (WHO, 2024)1
44%
are unaware they have it, about 600 million people1
#1
single largest risk factor for global disease burden2
11 mmHg
systolic reduction from the DASH dietary pattern in people with hypertension3
48.1%
of US adults have high blood pressure, about 119.9 million people, and only about 1 in 4 of them has it under control (CDC)18
20%
fewer major cardiovascular events for every 10 mmHg fall in systolic pressure, across 123 trials in 613,815 people19

Symptoms of High Blood Pressure

Hypertension rarely causes obvious symptoms until it's severe, which is why regular measurement matters.

SymptomWhat happens
Warning Symptoms (Severe Hypertension)
HeadachesHeadaches are an uncommon symptom of high blood pressure rather than a classic one, but frequent headaches are a reason to get your blood pressure checked25. These are medical emergencies when accompanied by visual changes or confusion.
Visual Disturbances & RetinopathyBlurred vision, seeing spots or sudden visual loss from hypertensive retinopathy, damage to the retinal blood vessels. An ophthalmologist can see early hypertensive changes in the retina before they become symptomatic.
Chest Pain & PalpitationsIn hypertensive crisis (BP >180/120), chest pain, palpitations and shortness of breath indicate cardiac strain. Any chest pain with high BP is an emergency; seek immediate medical care.
Nosebleeds (Epistaxis)Spontaneous nosebleeds from fragile nasal blood vessels under chronic pressure stress, more common in severe or uncontrolled hypertension. Not a reliable sign of high blood pressure on their own, as nosebleeds have many causes, but a reason to have your pressure checked.

Causes of High Blood Pressure

Most high blood pressure has no single cause; it builds from diet, weight, activity, alcohol, age and inherited risk acting together over years20.

CauseHow It Contributes to High Blood PressureWhat Helps
Too much sodium, too little potassiumEating too much sodium raises blood pressure, and so does eating too little potassium20; in the DASH-Sodium trial, each step down in sodium lowered systolic pressure further21Cutting processed and restaurant food, and eating more potassium-rich foods, as the diet section describes, with the kidney and medication cautions there
Excess weightObesity or overweight makes the heart work harder20; across 25 trials, each 2.2 lb (1 kg) lost lowered systolic pressure by about 1 mmHg22Gradual weight loss through the food pattern in the diet section and regular activity
AlcoholDrinking too much alcohol raises blood pressure20; in people drinking more than two drinks a day, cutting back lowered it, by about 5.5 mmHg systolic in heavy drinkers who halved their intake23Cutting down, as the diet section advises
Physical inactivityRegular activity keeps the heart and blood vessels healthy and may help lower blood pressure20Aerobic exercise most days, as in the treatment section
Age, family history and diabetesBlood pressure tends to rise with age and runs in families; about 6 in 10 people with diabetes also have high blood pressure20Age and family history cannot be changed, and diabetes needs its own treatment, so have regular checks, with treatment by your clinician when readings stay high

How High Blood Pressure Is Diagnosed

TestWhat it shows
At-Home Monitoring
Home BP Monitoring ProtocolTake readings twice daily (morning before medication, evening after rest) for 7 days. Sit quietly for 5 minutes, use a validated upper-arm cuff, measure twice per session and average. Readings taken outside the clinic are recommended to confirm the diagnosis before treatment starts, and they also reveal "white coat hypertension," pressure that is high only in the clinic26.
Tracking PatternsNote BP in relation to meals, stress, sleep, exercise, alcohol consumption and medication timing. Patterns can suggest what affects your readings and are worth showing your clinician; they cannot establish the cause on their own, and suspected sleep apnea needs a sleep study.
Clinical Tests
24-⁠Hour Ambulatory BP Monitor (ABPM)Wearable cuff measures BP every 20 to 30 minutes over 24 hours, capturing nocturnal dipping patterns (normal: 10 to 20% BP drop during sleep). Non-dipping is linked to kidney disease, sleep apnea and autonomic dysfunction. The most accurate diagnostic tool available.
Metabolic & Inflammatory PanelFasting glucose, HbA1c, fasting insulin, lipid panel with particle size (LDL-P), hs-CRP (inflammation marker), uric acid (predicts hypertension risk), kidney function (creatinine, eGFR), urine microalbumin (early kidney damage), thyroid panel, magnesium RBC level.
Cardiac & Vascular AssessmentEchocardiogram (checks for left ventricular hypertrophy, the heart enlarging under pressure load), carotid intima-media thickness (CIMT) ultrasound (measures arterial plaque and wall thickening) and ankle-brachial index (peripheral artery disease screening).

Conventional and Holistic Treatment for High Blood Pressure

๐ŸŒฟ HOLISTIC
๐Ÿ’Š CONVENTIONAL
๐ŸŒฟ

Holistic / Functional Approach

DASH diet, magnesium, CoQ10, berberine, hawthorn, hibiscus, stress reduction

BP Reduction Potential
DASH dietary pattern: about โˆ’11 mmHg systolic in people with hypertension3. Exercise and magnesium each add smaller amounts, but individual effects are not simply additive, so a combined total should not be assumed
Primary Herbs
Hawthorn berry, hibiscus flower, olive leaf, berberine, garlic extract
Timeline
In the DASH trial, the diet lowered blood pressure over an 8-⁠week feeding period.3
Side Effects
Few with food-based interventions; supplements can interact with medicines, and berberine interacts with many through CYP3A4 and P-glycoprotein

Full Holistic Approach Includes

  • DASH diet: reduces sodium to <2,300 mg/day, increases potassium, calcium and magnesium from whole foods
  • Magnesium glycinate (400 to 600 mg/day): relaxes arterial smooth muscle and reduces vascular resistance. This whole range is above the 350 mg/day upper intake level for supplemental magnesium; above that, diarrhea is common. With kidney disease, take it only on your clinician's advice.
  • CoQ10: supports mitochondrial energy in arterial walls. A Cochrane review found no clinically significant effect on blood pressure, so the large reductions often quoted for it are not well supported5
  • Hawthorn berry extract (500 to 1,500 mg/day), small and limited blood-pressure effects in trials; better studied for heart failure symptoms
  • Hibiscus flower tea: may act on the same pathway as ACE inhibitors. Meta-analyses report roughly 7 to 8.5 mmHg systolic reduction, though heterogeneity between trials is very high9
  • Olive leaf extract (500 to 1,000 mg/day), laboratory effects on ACE; human trials are small and few
  • Omega-⁠3 fish oil (3 to 4 g/day combined EPA+DHA): reduces inflammation, improves endothelial function, lowers triglycerides; at high doses fish oil can have an antiplatelet effect, so if you take a blood thinner, tell your prescriber, who may want your clotting (INR) checked periodically30. In heart trials, fish oil supplements raised the risk of atrial fibrillation, an irregular heartbeat, more so above 1 g a day31, so check this dose with your clinician first
  • Aerobic exercise 30+ minutes, 5 days/week, consistently among the better-evidenced interventions for sustained BP reduction
  • Stress management: meditation, yoga and diaphragmatic breathing activate the parasympathetic nervous system, reducing sympathetic BP drive
  • Weight loss (if overweight): each 2.2 lb (1 kg) lost reduces systolic BP by ~1 mmHg
โš ๏ธ Important: Never stop hypertension medications without physician supervision. Use holistic approaches alongside, not instead of, prescribed medications; any reduction in medication happens only when BP is consistently normal and your doctor agrees to a tapering plan.

Evidence-Based Supplements for High Blood Pressure

Each of the following has been studied for blood pressure, with results ranging from reasonably consistent to conflicting, as noted in each row. Effects are not simply additive. Used alongside diet and lifestyle change, they may contribute to a modest additional reduction. They are not a substitute for prescribed treatment, and no head-to-head comparison with medication supports treating them as one.

SupplementWhat it is forTypical rangeTimingNotes & cautions
Magnesium GlycinateMagnesium relaxes arterial smooth muscle by blocking calcium-mediated vasoconstriction, reduces sympathetic tone and improves insulin sensitivity. The size of the effect depends heavily on who is studied. A 2025 meta-analysis of 38 randomized trials in 2,709 people found a systolic reduction of about 2.8 mmHg overall, rising to roughly 7.7 mmHg in people already on blood-pressure medication and 6 mmHg in those who were magnesium deficient. An earlier pooled analysis found almost no effect at all, so treat this as modest and population-dependent rather than reliable.4Set with your prescriberWith dinner or before bedGlycinate is usually gentler on the gut than oxide, though any form can loosen stools at higher doses.
CoQ10 (Ubiquinol)An antioxidant that protects endothelial cells from oxidative damage. The evidence here does not support the large reductions often quoted. A Cochrane review found moderate-quality evidence that CoQ10 has no clinically significant effect on blood pressure: systolic −3.7 mmHg with a confidence interval crossing zero. A later GRADE-assessed meta-analysis found about −4.8 mmHg in cardiometabolic disease, rated moderate to very low certainty.5 It remains of interest for people taking statins, which deplete CoQ10, but that is a different question from lowering blood pressure.Set with your prescriberWith a fat-containing meal, fat required for absorptionUbiquinol is the reduced form. CoQ10 may interact with some blood thinners and with insulin, so check with your prescriber first if you take either29.
Omega-⁠3 Fish Oil (EPA+DHA)Omega-⁠3s improve endothelial nitric oxide production, reduce vascular inflammation and lower triglycerides. A 2022 meta-analysis of 71 trials found a systolic reduction of about 2.6 mmHg, with larger intakes more effective.6 A real but small effect; useful as part of a pattern rather than on its own.Set with your prescriberWith mealsChoose a third-party tested, molecularly distilled product. Enteric coating reduces fishy aftertaste. Prescription omega-⁠3 (EPA-only) is used for severe hypertriglyceridemia. At high doses fish oil can have an antiplatelet effect, so tell your prescriber if you take a blood thinner30. In heart trials, fish oil supplements raised the risk of atrial fibrillation, an irregular heartbeat, more so above 1 g a day31, so check this dose with your clinician first.
Aged Garlic ExtractAged garlic contains S-allylcysteine, which has ACE-inhibitory and vasodilatory activity. Pooling 12 trials in 553 adults with high blood pressure gives a systolic reduction of about 8.3 mmHg and diastolic about 5.5 mmHg.7 Single trials have reported larger figures; the pooled estimate is the more reliable number.Set with your prescriberWith foodAged form (not raw garlic) has little odor and is the form used in most blood-pressure trials. Garlic supplements may increase the risk of bleeding, so talk to your prescriber first if you take a blood thinner or have surgery planned28.
Hawthorn Berry ExtractHawthorn (Crataegus monogyna) contains proanthocyanidins and vitexin, which dilate peripheral arteries and reduce vascular resistance. Trial evidence for blood pressure specifically is limited and the reported effects are small, on the order of a few mmHg diastolic. Better studied for heart failure symptoms than for hypertension.8Set with your prescriberWith meals, divided dosesMay enhance the effect of cardiac medications; monitor if on cardiac glycosides or nitrates.
Hibiscus Flower ExtractHibiscus sabdariffa anthocyanins appear to act as natural ACE inhibitors. Meta-analyses report a systolic reduction of roughly 7 to 8.5 mmHg, with the largest effects in those whose blood pressure was highest to begin with. Read the figure with care: heterogeneity between trials is very high, so the true effect is less certain than the headline number suggests.9Set with your prescriberAfter mealsDeep red tart tea. Avoid if on a thiazide diuretic, possible interaction.
BerberineBerberine activates AMPK, reduces insulin resistance and inhibits ACE activity. The evidence conflicts. A 2022 meta-analysis found a systolic reduction of about 5.5 mmHg10, while a 2025 meta-analysis of placebo-controlled trials found no significant effect on either systolic or diastolic pressure in the three trials that measured it.32 Berberine also interacts with many prescription medicines through CYP3A4 and P-glycoprotein, so it is not a casual addition.Set with your prescriberWith mealsEvidence for blood pressure conflicts between meta-analyses. Monitor blood glucose; berberine can cause hypoglycemia when combined with diabetes medication. Not for use in pregnancy or breastfeeding.
Olive Leaf Extract (OLE)Oleuropein, the main polyphenol in olive leaf, inhibits ACE and reduces arterial stiffness in laboratory work. Human trials are small and few, so treat any specific blood-pressure figure for olive leaf as provisional.11Set with your prescriberWith mealsChoose a standardized extract with โ‰ฅ20% oleuropein. Avoid very high doses (over 2 g/day), which may cause GI upset.
Potassium (from food or supplement)Potassium promotes sodium excretion and relaxes vascular smooth muscle. The effect depends on who you are: in people with hypertension, a meaningful increase in intake lowers systolic pressure by roughly 4.5 to 5 mmHg, while in people with normal blood pressure the effect is close to zero. The relationship is also U-shaped, so more is not better and very high intakes can raise pressure again.12 Potassium supplements are dangerous with ACE inhibitors, ARBs, potassium-sparing diuretics or reduced kidney function. Food first, and supplements only with your prescriber.Food sources first. Any supplement only with your prescriber.With mealsDo not supplement if you have kidney disease or are on ACE inhibitors/ARBs/potassium-sparing diuretics, risk of hyperkalemia.

What to Expect Over Time

Diet, weight and activity changes and prescribed medication work together, and this is what trials show about the pace for adults with high blood pressure.

Treatment and supportive care, together
First Weeks

Diet change acts quickly: in the DASH-Sodium trial, blood pressure was lower within each 30-⁠day diet period on the DASH pattern and on lower sodium21. Home readings show the trend; never stop or change a blood-pressure medicine on the strength of them without your prescriber.

Months 1 to 3

In the original DASH trial, eight weeks of the diet lowered systolic pressure by 11.4 mmHg more than the control diet in people with hypertension3. A single medicine at standard dose lowers it by about 9 mmHg on average, and different classes add together16.

Months 3 to 12

Guidelines advise reassessing blood pressure 3 to 6 months after starting lifestyle change24. Each 2.2 lb (1 kg) lost lowers systolic pressure by about 1 mmHg22; many people with established hypertension also need medication.

Long Term

Every 10 mmHg fall in systolic pressure cut major cardiovascular events by about 20% and stroke by about 27% in trials19. The benefit depends on keeping the changes going21.

When to Seek Care

Call 911 for chest pain that does not go away, pain spreading to the arm, neck, jaw or back, or chest pain with sweating, nausea, lightheadedness or breathlessness, and for any sign of stroke: face drooping, arm weakness or slurred speech. Call 911 too for a severe headache with blurred vision or confusion, or for sudden loss of sight, which can be signs of a stroke25. Get prompt advice for frequent headaches or blurred vision25.

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Lowering Blood Pressure With Diet and Lifestyle

High blood pressure is not a life sentence. A comprehensive approach, targeting diet, inflammation, stress and metabolic health, can lower blood pressure meaningfully and, with your prescriber, sometimes allow a lower medication dose.

References & Evidence Notes

Each numbered entry below is either a source you can follow or a note setting out what the evidence does and does not support. Both are numbered together so the markers in the text line up.

Last reviewed October 20, 2026. Blood-pressure thresholds follow the ACC/AHA guideline.13 Supplement entries are cross-checked against the NIH National Center for Complementary and Integrative Health and the Linus Pauling Institute Micronutrient Information Center.15 This page is nutrition education, not medical advice, and it does not replace your doctor. If you take blood-pressure medication, do not change or stop it, and do not add a supplement, without speaking to your prescriber. Several of the supplements below interact with common antihypertensives.

  1. World Health Organization. Hypertension fact sheet and Global report on hypertension. who.int. An estimated 1.4 billion adults aged 30 to 79 have hypertension; about 44% are unaware. ↩ ↩
  2. Lim SS, et al. and subsequent Global Burden of Disease analyses identifying high blood pressure as the leading single risk factor for global disease burden. PubMed 23536128. ↩
  3. Appel LJ, et al. A clinical trial of the effects of dietary patterns on blood pressure (DASH). N Engl J Med. 1997;336:1117-⁠1124. nejm.org. In the trial, 459 adults were fed the study diets for eight weeks, and among the 133 with hypertension the combination diet lowered systolic pressure by 11.4 mmHg more than the control diet, PubMed 9099655. See also Sacks FM, et al. N Engl J Med. 2001;344:3-⁠10, on DASH combined with sodium reduction. ↩
  4. Magnesium supplementation and blood pressure: a systematic review and meta-analysis of randomized controlled trials. Hypertension. 2025. ahajournals.org. Contrast with the earlier pooled analysis in Am J Hypertens. 2002;15(8):691, which found almost no effect. ↩
  5. Ho MJ, et al. Coenzyme Q10 for high blood pressure. Cochrane Database Syst Rev. cochrane.org: moderate-quality evidence of no clinically significant effect. See also the GRADE-assessed dose-response meta-analysis, ScienceDirect. ↩ ↩
  6. Zhang X, Ritonja JA, Zhou N, Chen BE, Li X. Omega-⁠3 polyunsaturated fatty acids intake and blood pressure: a dose-response meta-analysis of randomized controlled trials. J Am Heart Assoc. 2022;11(11):e025071. PMC9238708. 71 randomized trials; about 2.6 mmHg lower systolic pressure at 2 to 3 g a day. ↩
  7. Ried K. Garlic lowers blood pressure in hypertensive subjects: an updated meta-analysis. Exp Ther Med. Twelve trials, 553 adults, about 8.3 mmHg systolic. ↩ ↩
  8. Hawthorn (Crataegus) reviews report limited and small blood-pressure effects; the stronger evidence base is in heart failure symptom management. See NCCIH, ref. 15. ↩
  9. Ellis LR, et al. A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers. Nutrition Reviews. 2022;80(6):1723. Oxford Academic. Note the very high between-trial heterogeneity. ↩ ↩
  10. The effects of berberine supplementation on cardiovascular risk factors in adults: a systematic review and dose-response meta-analysis. Front Nutr. 2022. frontiersin.org. Contrast with the later 2025 meta-analysis of placebo-controlled trials (note 32), which found no significant blood-pressure effect. ↩
  11. Olive leaf extract trials for blood pressure are small and few; see NCCIH, ref. 15, for the current assessment. ↩
  12. Filippini T, et al. Potassium intake and blood pressure: a dose-response meta-analysis of randomized controlled trials. J Am Heart Assoc. 2020. ahajournals.org. Note the U-shaped relationship and the near-absent effect in people with normal blood pressure. ↩
  13. Whelton PK, et al. 2017 ACC/AHA guideline for the prevention, detection, evaluation and management of high blood pressure in adults, which sets the 130/80 mmHg threshold. ahajournals.org. ↩
  14. Effects of oral berry supplementation on blood pressure in adults with hypertension or elevated blood pressure: a systematic review and meta-analysis of randomized controlled trials. PMC13209865. See also the anthocyanin review of 44 RCTs and 15 cohorts, PMC8714924. ↩
  15. National Center for Complementary and Integrative Health (NIH), nccih.nih.gov, and the Linus Pauling Institute Micronutrient Information Center, lpi.oregonstate.edu/mic. ↩
  16. On how much blood-pressure drugs lower pressure: a meta-analysis of 354 randomized placebo-controlled trials of the five main drug classes found an average systolic reduction of 9.1 mmHg at standard dose, found that the effects of different classes add together, and estimated that three drugs at half standard dose would lower systolic pressure by 20 mmHg from a starting pressure of 150/90 mmHg, PubMed 12829555. ↩
  17. On how much potassium: the 2019 National Academies review of sodium and potassium set adequate intakes for adults of 3,400 mg a day for men and 2,600 mg for women, updated from the 2005 values, and warned against high intake through supplemental potassium for people with or at high risk of compromised kidney function, PubMed 30844154. ↩
  18. On how common high blood pressure is in the US: the CDC reports that 48.1% of adults, about 119.9 million people, have high blood pressure, and that about 1 in 4 of them, 22.5%, has it under control, CDC, High Blood Pressure Facts. ↩
  19. On what lowering blood pressure prevents: a 2016 meta-analysis of 123 trials in 613,815 people found that every 10 mmHg reduction in systolic pressure lowered major cardiovascular events by 20%, coronary heart disease by 17%, stroke by 27% and heart failure by 28%, PubMed 26724178. ↩
  20. On what raises blood pressure: the CDC lists too much sodium, too little potassium, too little physical activity, overweight or obesity, too much alcohol, tobacco use, family history and age as risk factors, and notes that about 6 in 10 people with diabetes also have high blood pressure, CDC, High Blood Pressure Risk Factors. ↩
  21. On sodium and the DASH diet: in the DASH-Sodium trial, 412 adults ate a typical US diet or the DASH diet at high, intermediate and low sodium for 30 days each; lower sodium and the DASH diet each lowered blood pressure, and together the DASH diet with low sodium gave systolic pressure 11.5 mmHg lower in people with hypertension than the typical diet with high sodium. The authors note that long-term benefit depends on lasting dietary change, PubMed 11136953. ↩
  22. On weight loss and blood pressure: a 2003 meta-analysis of 25 randomized trials in 4,874 adults found that systolic pressure fell by about 1.05 mmHg and diastolic by about 0.92 mmHg for each 2.2 lb (1 kg) of weight lost, PubMed 12975389. ↩
  23. On cutting down alcohol: a 2017 meta-analysis of 36 trials in 2,865 adults found no significant blood pressure change from cutting down in people drinking two or fewer drinks a day, but a fall in those drinking more, largest, about 5.5 mmHg systolic, in people drinking six or more a day who halved their intake, PubMed 29253389. ↩
  24. On when to recheck: the 2017 ACC/AHA blood pressure guideline recommends reassessing people who have been prescribed lifestyle and risk-factor changes after 3 to 6 months, as summarized in Cleveland Clinic Journal of Medicine, 2018. ↩
  25. On when to get help: NHS guidance advises calling emergency services for chest pain that does not go away, pain spreading to the arm, neck, jaw, stomach or back, or chest pain with sweating, nausea, lightheadedness or breathlessness, and seeking advice for frequent headaches or blurred vision; for stroke it uses FAST (face, arms, speech, time to call), NHS, high blood pressure and NHS, stroke symptoms. ↩
  26. On confirming the diagnosis: the US Preventive Services Task Force recommends screening adults for high blood pressure with office measurement, and obtaining measurements outside the clinical setting to confirm the diagnosis before treatment starts, PubMed 33904861. ↩
  27. On cough with ACE inhibitors: an evidence-based clinical practice guideline reports that a dry, persistent cough is a class effect of these medicines, with an incidence of 5 to 35% in treated patients, that it can start within hours or months after the first dose, and that it usually resolves within 1 to 4 weeks of stopping, though it may linger for up to 3 months; the cough rate with angiotensin receptor blockers is similar to placebo, PubMed 16428706. ↩
  28. On garlic and bleeding: the NIH National Center for Complementary and Integrative Health states that garlic supplements may increase the risk of bleeding, which matters before surgery and for anyone taking medicines that also affect bleeding, such as anticoagulants, NCCIH, Garlic. ↩
  29. On CoQ10 and other medicines: the NIH National Center for Complementary and Integrative Health states that CoQ10 may interact with a commonly used blood thinner and with insulin, NCCIH, Coenzyme Q10. ↩
  30. On fish oil and blood thinners: the NIH Office of Dietary Supplements notes that fish oil can have antiplatelet effects at high doses and might prolong clotting times in people taking an anticoagulant, although most research finds 3 to 6 g a day does not significantly change anticoagulant status, and that people taking omega-⁠3 products with an anticoagulant should have their INR monitored periodically, NIH ODS, Omega-⁠3 Fatty Acids. ↩
  31. Gencer B, Djousse L, Al-Ramady OT, Cook NR, Manson JE, Albert CM. Effect of long-term marine omega-⁠3 fatty acids supplementation on the risk of atrial fibrillation in randomized controlled trials of cardiovascular outcomes: a systematic review and meta-analysis. Circulation. 2021;144(25):1981-⁠1990. PubMed 34612056. Seven trials with 81,210 people followed for about 5 years: omega-⁠3 supplements were linked to a higher risk of atrial fibrillation (hazard ratio 1.25), more so in trials of more than 1 g a day (1.49), and the risk rose with each additional gram. ↩
  32. Liu D, Zhao H, Zhang Y, Hu J, Xu H. Efficacy and safety of berberine on the components of metabolic syndrome: a systematic review and meta-analysis of randomized placebo-controlled trials. Front Pharmacol. 2025;16:1572197. PubMed 40740996. Twelve placebo-controlled trials with 889 people: berberine lowered triglycerides, fasting glucose and waist size but had no significant effect on systolic or diastolic blood pressure, which three of the trials measured. ↩