Sea Buckthorn: What the Evidence Actually Says About Benefits, Uses, and Safety

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Sea buckthorn is a thorny shrub whose bright orange berries hold one of the richest natural stores of vitamin C of any fruit. People across Europe and Asia have used it for centuries, and modern labs confirm it is genuinely nutrient-dense. But most of the bolder health claims attached to it rest on animal and test-tube work, not human trials.

This guide separates what the research actually supports from what is still guesswork, shows how people use the berry and its oil, and flags the safety points that matter — including a drug interaction worth knowing about.

The plant and its odd name

Sea buckthorn (Hippophae rhamnoides) is a deciduous, spiny shrub in the Elaeagnaceae family. It grows roughly one to six meters tall, with narrow silver-green leaves and dense clusters of yellow-orange berries. Male and female flowers grow on separate plants, so only female shrubs bear fruit. The plant is native across temperate Eurasia — from the Atlantic coast through the Himalayas into China and Mongolia — and has naturalized in parts of North America. [Wang et al., 2022]

The genus name comes from the Greek hippos, “horse,” and phaos, “to shine.” Ancient Greeks fed the leaves to horses and noticed their coats grew glossier, which is how the shrub earned a name that roughly means “shining horse.” [Chen et al., 2024] You may run across a folk story that the name means “horse killer.” That isn’t supported — sea buckthorn is not a recognized horse poison.

What’s actually in the berry

Sea buckthorn’s reputation starts with vitamin C. The amount swings widely with subspecies, ripeness, and growing region: published figures run from about 200 to 1,500 mg per 100 g of fresh berries, with a frequently cited average near 400 mg. [Gutzeit et al., 2008] Even at the low end, that is several times the roughly 53 mg in 100 g of lemon or orange. It ranks among the richest fruit sources known — though not the single highest, since acerola and rose hips can beat it. If you want the bigger picture, see our roundup of foods rich in vitamin C.

The berry and its oils carry far more than vitamin C:

Compound	Why it matters
Vitamin C	Antioxidant that supports immune function and collagen formation.
Carotenoids (beta-carotene, lycopene, zeaxanthin)	Orange pigments; some convert toward vitamin A in the body.
Vitamin E (tocopherols and tocotrienols)	Fat-soluble antioxidants that help protect cell membranes.
Vitamin K and B vitamins	Involved in blood clotting and energy metabolism.
Flavonoids (isorhamnetin, quercetin)	Plant antioxidants studied for anti-inflammatory effects.
Omega-7 (palmitoleic acid)	An unusual fatty acid concentrated in the oil, studied for skin and metabolic effects.
Omega-3, -6, and -9	Sea buckthorn is one of the few plants supplying all of them.

One practical note: oil pressed from the seeds and oil pressed from the pulp differ in fatty-acid makeup, so products labeled “seed oil” and “berry” or “pulp oil” are not interchangeable.

What the research supports — and what it doesn’t

Here is the honest picture. A handful of small human trials point to real but modest benefits in a few specific areas. The dramatic claims — that sea buckthorn fights cancer, reverses liver disease, or protects the heart — come from cell and animal studies that have not been confirmed in people. [Wang et al., 2022] [Chen et al., 2024]

Use	Evidence level	What studies show
Dry eye	Moderate (small human RCTs)	In a 3-month trial of 100 adults, 2 g/day of oral oil slowed the seasonal rise in tear-film saltiness and eased redness and burning versus placebo [Larmo et al., 2010]. A separate trial of a topical eyelid spray also reduced symptoms [Larmo et al., 2019].
Skin comfort and atopic dermatitis	Limited / mixed	Small trials suggest oral oil may modestly improve skin hydration and dermatitis symptoms, with effects tied to changes in skin fatty acids [Yang et al., 1999].
Cholesterol, blood pressure, blood sugar	Early / mixed	In people who already have abnormal lipids or high blood pressure, some trials show small improvements; in healthy people, no clear effect. Large, multicenter trials are lacking [Chen et al., 2024].
Cancer, liver protection, wound healing, antiviral	Preclinical only	Promising in lab and animal models, but not established in humans [Wang et al., 2022].

The strongest signal so far is for dry eye, and even there the benefit was modest rather than curative. Treat anything below that line as a maybe, not a given. If dry eye is your reason for trying it, it’s also worth reading up on broader eye and vision health.

How people take it

You can eat ripe berries straight, but they are sharply sour, so most people reach for juice, purée, jam, dried powder, or capsules of the oil. A traditional preparation simmers the juice into a sweetened syrup; if you go that route, our guide to preparing herbs at home covers the basics. Doses used in research give a rough reference, not a prescription:

• Dry eye trials used about 2 g of oil daily for three months. [Larmo et al., 2010]
• Atopic dermatitis studies used around 5 g of seed or pulp oil daily for four months. [Yang et al., 1999]
• Cardiometabolic studies used a few grams of oil, or the dried equivalent of roughly 100 g of fresh berries, over several weeks.

For topical use, the oil is deep orange and can temporarily stain skin and fabric. Dab a little on your inner forearm and wait a few hours before wider use, since botanical oils can irritate sensitive skin.

Safety, side effects, and interactions

Across published trials, sea buckthorn oil has been well tolerated, with no serious adverse effects reported. [Wang et al., 2022] The cautions that do exist are worth taking seriously.

Bleeding risk is the main one. Sea buckthorn appears to slow blood clotting and reduce platelet stickiness. On its own that effect is mild, but combined with blood thinners or antiplatelet drugs — warfarin, aspirin, clopidogrel — or with supplements like garlic, ginkgo, or high-dose fish oil, it can add up. [WebMD, 2025] Stop taking concentrated sea buckthorn at least two weeks before any surgery.

It may also nudge blood pressure and blood sugar downward. If you take medication for high blood pressure or diabetes, that overlap can push your levels too low, so monitor closely and talk with your prescriber. [WebMD, 2025] [Olas, 2018]

At high oil doses, some people get loose stools or mild stomach upset. The oil’s orange pigment can briefly tint stool — harmless, but startling the first time.

Who should be cautious or avoid it

• Anyone on anticoagulant or antiplatelet medication, or with a bleeding disorder.
• People scheduled for surgery within the next two weeks.
• Anyone taking blood-pressure or diabetes medication, unless a clinician is guiding the dose.
• People who are pregnant or breastfeeding: culinary amounts of the berry are likely fine, but there isn’t enough safety data on concentrated oil or supplements, so the cautious choice is to skip those unless a clinician says otherwise. [WebMD, 2025]

One older folk recommendation pairs sea buckthorn with foxglove (digitalis) heart remedies. Don’t. Foxglove-derived drugs have a narrow safety margin, and adding an herb that can affect blood pressure and clotting alongside them is risky. Heart conditions need a doctor’s supervision, not herbal layering.

What to realistically expect

Sea buckthorn is a nutrient-dense food and a solid source of vitamin C, vitamin E, and some unusual fatty acids. If you have dry eye, the oil has the best odds of helping — and even then the trial effect was modest, not a cure. As a general “tonic,” it behaves like most whole-food supplements: a reasonable addition to a varied diet, not a shortcut around medical care for a diagnosed condition.

When to talk to a healthcare professional

Check with a clinician or pharmacist before starting sea buckthorn supplements if you take prescription medication — especially blood thinners, blood-pressure drugs, or diabetes medication — or if you are pregnant, nursing, or heading into surgery. And if you’re using it to manage a real condition such as dry eye or high cholesterol, treat it as an add-on to discuss with your doctor, not a replacement for proven treatment.

Health Disclaimer This article is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Sea buckthorn supplements can interact with prescription medications — particularly blood thinners, blood-pressure drugs, and diabetes medication. If you are pregnant, breastfeeding, scheduled for surgery, or managing any health condition, talk to a qualified healthcare professional before using sea buckthorn or any herbal product. Never delay or stop prescribed treatment based on information you read here.

Frequently Asked Questions

References

1. Olas B. The beneficial health aspects of sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson) oil. Journal of Ethnopharmacology. 2018;213:183–190.  → View source
2. Wang Z, Zhao F, Wei P, et al. Phytochemistry, health benefits, and food applications of sea buckthorn (Hippophae rhamnoides L.): a comprehensive review. Frontiers in Nutrition. 2022;9:1036295.  → View source
3. Larmo PS, Järvinen RL, Setälä NL, et al. Oral sea buckthorn oil attenuates tear film osmolarity and symptoms in individuals with dry eye. The Journal of Nutrition. 2010;140(8):1462–1468.  → View source
4. Yang B, Kalimo KO, Mattila LM, et al. Effects of dietary supplementation with sea buckthorn (Hippophae rhamnoides) seed and pulp oils on atopic dermatitis. The Journal of Nutritional Biochemistry. 1999;10(11):622–630.  → View source
5. Larmo PS, Yang B, Hyssälä J, et al. Effects of a sea buckthorn oil spray emulsion on dry eye. Contact Lens and Anterior Eye. 2019;42(4):428–433.  → View source
6. Chen Y, He W, Cao H, et al. Research progress of sea buckthorn (Hippophae rhamnoides L.) in prevention and treatment of cardiovascular disease. Frontiers in Cardiovascular Medicine. 2024;11:1477636.  → View source
7. Gutzeit D, Baleanu G, Winterhalter P, Jerz G. Vitamin C content in sea buckthorn berries (Hippophae rhamnoides L. ssp. rhamnoides) and related products: a kinetic study on storage stability and the determination of processing effects. Journal of Food Science. 2008;73(9):C615–C620.  → View source
8. WebMD. Sea Buckthorn: Uses and Risks. Reviewed 2025.  → View source