Supplements to strengthen blood vessels are everywhere online, and the promises are big. The research is a lot more modest. A few products help with specific problems, but most have little proof behind them.
This guide sorts popular supplements to strengthen blood vessels by how strong the evidence really is. It also covers blood thinner interactions and the habits that do more for your veins and arteries than any capsule.
Key takeaways
- None of the supplements to strengthen blood vessels has been shown to make healthy vessels stronger. Be wary of products that promise it.
- Horse chestnut seed extract has the best evidence for tired, swollen legs caused by weak veins, but only for short-term use.
- Walking, not smoking, less salt and a healthy weight protect your vessels more than any supplement.
Do supplements to strengthen blood vessels work?
No supplements to strengthen blood vessels have been proven to make healthy vessels stronger. A few have modest evidence for specific problems: horse chestnut seed extract for leg swelling from weak veins, omega-3s for triglycerides, and dietary nitrate for blood pressure. For most people, exercise, not smoking and food choices matter more.
Supplements to strengthen blood vessels at a glance
I ranked each option by what systematic reviews and health agencies say. “Moderate” means decent trials with caveats. “Weak” means mixed or indirect results.
| Supplement | What the research shows | Evidence strength | Watch-outs |
|---|---|---|---|
| Horse chestnut seed extract | Reduced leg pain and swelling in short placebo-controlled trials of chronic venous insufficiency | Moderate (short term) | Raw plant parts are toxic. Dizziness, stomach upset, itching |
| Purified flavonoid fraction (often diosmin-based) | Best-supported of the vein-active drugs for symptoms and signs in an umbrella review | Moderate | Often a prescribed product. Ask your doctor |
| Omega-3 (fish oil) | Lowers triglycerides about 15%. Slight drop in coronary events. Little effect on blood pressure | Moderate for triglycerides, low to moderate for heart events | Fishy aftertaste, heartburn, diarrhoea. Ask about blood thinners |
| Dietary nitrate (beetroot, leafy greens) | Lowered blood pressure by about 5/2 mmHg and eased arterial stiffness on average | Moderate for blood pressure, unproven for outcomes | Studied mostly as food and juice, not pills |
| Vitamin K2 | Slowed coronary calcification in some trials. One kidney trial found no stiffness benefit | Weak to moderate | Do not take vitamin K supplements on warfarin |
| Garlic | Small drops in cholesterol. Limited evidence for blood pressure | Weak | May raise bleeding risk |
| Vitamin C | No proven vessel benefit from pills. Most people get enough from food | Weak | Over 1,000 mg a day can upset the stomach |
| Vitamin E | A US panel found no net benefit for preventing heart disease | Not supported | High doses are not advised |
Supplements for varicose veins and swollen legs
Varicose veins form when the valves that keep blood moving in your veins stop working properly, according to the NHS. Supplements cannot close a damaged valve. They may ease heaviness and swelling, though.
Horse chestnut seed extract
This is the best-studied option. A Cochrane review of horse chestnut seed extract for chronic venous insufficiency found it effective and safe in the short term. Six of seven placebo-controlled trials showed less leg pain.
Leg volume also dropped by about 32 ml more than with placebo across six trials of 502 people. The authors still asked for larger studies.
The NCCIH says standardised extracts look safe for up to 12 weeks. Raw seeds, bark, flowers and leaves are toxic to swallow.
Diosmin and other flavonoids
Rutin and diosmin are plant flavonoids. An umbrella review of 11 systematic reviews found several vein-active drugs beat placebo for swelling and pain. A micronised purified flavonoid fraction had the most complete evidence.
Do vitamins for blood vessels actually work?
The US Preventive Services Task Force reviewed vitamin and mineral pills for preventing heart disease. It found no net benefit from vitamin E and advised against beta carotene.
For multivitamins and other single or paired nutrients, it found the evidence insufficient to judge. Nothing there shows that a vitamin pill makes vessels stronger.
Vitamin C. The NHS says adults aged 19 to 64 need about 40 mg a day and should get it from food, such as peppers, citrus and broccoli. Taking under 1,000 mg a day is unlikely to harm you. Pills have no proven vessel benefit.
Vitamin E. The NHS says you need 3 to 4 mg a day, which food covers easily. It also notes the effects of high doses are unclear. Nuts, seeds and plant oils are the better route.
B vitamins, CoQ10, grape seed and Pycnogenol. The old version of this post praised them as supplements to strengthen blood vessels. I could not verify those claims from reliable sources, so I removed them. If you suspect low B12, read our guide on B12 deficiency signs.
Omega-3, nitrate, vitamin K2 and garlic: what the trials show
Omega-3 fish oil
A 2020 Cochrane review pooled 86 trials with 162,796 people. Long-chain omega-3s made little or no difference to deaths or total cardiovascular events. They may slightly cut coronary heart disease deaths and events.
They lowered triglycerides by about 15%. Effects on blood pressure were minimal. The NCCIH lists a bad taste, bad breath, heartburn and diarrhoea as common side effects.
Beetroot and dietary nitrate
A meta-analysis of 34 studies found that nitrate from foods like beetroot and spinach lowered systolic blood pressure by 4.8 mmHg and diastolic by 1.7 mmHg on average. It also improved vessel widening and reduced arterial stiffness.
Vitamin K2
A 2023 review of 14 trials with 1,533 people found vitamin K slowed coronary artery calcification progression. A 2019 meta-analysis also reported a small reduction in vascular calcification.
Not every trial agreed. In 159 people with kidney disease, 400 mcg of K2 daily for a year did not improve artery stiffness. The reviewers called for bigger trials.
The NHS says 1 mg or less of vitamin K supplements a day is unlikely to harm most people. It also says not to take vitamin K supplements while on warfarin.
Garlic
The NCCIH says garlic supplements may lower total and LDL cholesterol slightly. Evidence for blood pressure is limited. It also warns that garlic supplements may increase bleeding risk, especially around surgery or with blood thinners.
Are supplements safe with blood thinners?
Not automatically. If you take warfarin, aspirin or another blood thinner, check every supplement first. The NHS tells warfarin users to avoid vitamin K supplements and St John’s wort, and to avoid cranberry and grapefruit juice.
Garlic supplements may add to bleeding risk, per the NCCIH. For fish oil, vitamin E and horse chestnut, I found no clear interaction data on the pages I opened. That is a reason to ask, not a green light.
- Tell your doctor and pharmacist about every product, including herbal ones.
- Do not stop a prescribed medicine to try a supplement.
- Get advice before surgery about what to stop.
- Check the label for the actual amount of each ingredient.
Better than supplements to strengthen blood vessels: daily habits
Health agencies point to lifestyle first. The NHLBI lists nutrition, weight, physical activity, stress, quitting smoking and sleep as the pillars of heart-healthy living. None of these come in a bottle.
- Move regularly. The CDC says adults need at least 150 minutes of moderate activity a week, plus muscle-strengthening on 2 or more days.
- For leg veins. The NHS suggests regular walking or running, raising your legs when resting, compression stockings, a healthy weight and avoiding long spells of standing or sitting.
- For blood pressure. The NHS advises less salt, more fruit and vegetables, no more than 14 alcohol units a week and not smoking.
- For leg pain when walking. For peripheral arterial disease, the NHS lists supervised exercise, about 2 hours a week for 3 months, as an early step. It also stresses stopping smoking.
- Manage stress. Slow breathing and calming routines help. Try our nervous system reset techniques.
When to see a doctor
Book an appointment if your legs hurt, itch or swell, or if a sore has not healed in two weeks, as the NHS advises. Get urgent care if a varicose vein is bleeding.
Frequently asked questions
What vitamins are good for blood vessels?
Your vessels need a balanced diet with vitamins C and K from food. Pills have not been shown to prevent heart disease. A US task force found no net benefit from vitamin E and insufficient evidence for most other single vitamins.
What supplements help with circulation?
Horse chestnut seed extract and purified flavonoid products may ease swelling from poor vein function. Dietary nitrate from beetroot and leafy greens lowers blood pressure slightly. Walking regularly is still the proven way to improve circulation.
What supplements are good for varicose veins?
Supplements cannot repair damaged vein valves. Horse chestnut seed extract and diosmin-type flavonoids may reduce pain and swelling. The NHS recommends exercise, leg elevation, compression stockings and a healthy weight, and lists treatments for stubborn cases.
Can I take fish oil or garlic with blood thinners?
Check first. The NCCIH warns garlic supplements may increase bleeding risk. Ask your doctor or pharmacist about fish oil too. Never add or stop anything without telling the person managing your blood thinner.
The bottom line
No supplements to strengthen blood vessels have been shown to make healthy vessels stronger, so be wary of big promises. Horse chestnut has the best evidence for tired, swollen legs, and garlic, vitamin K and fish oil need a doctor’s check if you take blood thinners. Walking, not smoking, less salt and a healthy weight do more than any capsule.
Supplements can interact with medicines and are not right for everyone. Check with your doctor or pharmacist before starting any supplements to strengthen blood vessels, especially if you take blood thinners, are pregnant or have a health condition.
Related reading
Sources
- NCCIH. Horse Chestnut.
- Pittler MH, Ernst E. Horse chestnut seed extract for chronic venous insufficiency. Cochrane Database Syst Rev, 2012.
- Mansilha A, et al. Pharmacological treatment for chronic venous disease: an umbrella review. Int Angiol, 2022.
- Abdelhamid AS, et al. Omega-3 fatty acids for the prevention of cardiovascular disease. Cochrane Database Syst Rev, 2020.
- NCCIH. Omega-3 Supplements: What You Need To Know.
- Jackson JK, et al. The role of inorganic nitrate and nitrite in cardiovascular disease risk factors. Nutr Rev, 2018.
- Te L, et al. Vitamin K supplementation and vascular calcification. Front Nutr, 2023.
- Lees JS, et al. Vitamin K status, supplementation and vascular disease: a systematic review and meta-analysis. Heart, 2019.
- Witham MD, et al. The K4Kidneys randomized controlled trial. J Am Soc Nephrol, 2020.
- NCCIH. Garlic.
- US Preventive Services Task Force. Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer. JAMA, 2022.
- NHS. Varicose veins.
- NHS. Preventing high blood pressure.
- NHS. Peripheral arterial disease: treatment.
- NHS. Warfarin.
- NHS. Vitamin C.
- NHS. Vitamin E.
- NHS. Vitamin K.
- NHLBI. Heart-Healthy Living.
- CDC. Physical Activity Guidelines for Adults.