Sea Buckthorn: Omega-7 and the Dry-Eye Evidence
Sea buckthorn is a thorny shrub that grows where almost nothing else will — coastal dunes, cold mountain slopes, roadside gravel. Its oil contains a fatty acid most foods do not, and it carries the one piece of eye-specific human evidence in the OptiPlax blend.
- Botanical name
- Hippophae rhamnoides
- Part used
- Berry and seed oil
What sea buckthorn is
Hippophae rhamnoides is a hardy deciduous shrub native to a band running from Western Europe across Central Asia to China. It fixes nitrogen, tolerates salt, drought and cold, and is widely planted for erosion control — including on a very large scale in China.
The berries are bright orange, intensely sour, and cling so tightly to thorny branches that harvesting is genuinely difficult; branches are often frozen and shaken rather than picked. That harvesting problem is a large part of why the oil is expensive.
The berries have a long history in Central Asian and Tibetan traditional medicine, and in Russia, Scandinavia and Germany they are an ordinary food — juice, jam and syrup.
Omega-7 and the two different oils
Sea buckthorn is one of very few plant sources of palmitoleic acid, an omega-7 monounsaturated fatty acid. Most dietary fats are omega-3, omega-6 or omega-9; omega-7 is uncommon enough that sea buckthorn is often the reason it appears in a formula at all.
Importantly, sea buckthorn yields two quite different oils:
| Pulp / berry oil | Seed oil | |
|---|---|---|
| Colour | Deep orange-red | Pale yellow |
| Dominant fats | Palmitoleic acid (omega-7), palmitic acid | Linoleic and alpha-linolenic acid (omega-6 and omega-3) |
| Carotenoids | High | Low |
A label that simply says “sea buckthorn oil” without specifying which is leaving out a meaningful difference. The berries are also exceptionally high in vitamin C — by most measures several times the concentration in citrus.
The dry-eye research
This is the strongest eye-specific evidence in the OptiPlax formula, and it is worth describing precisely rather than overselling.
Finnish researchers ran randomised, placebo-controlled trials giving roughly 2 g of sea buckthorn oil daily over three months to people with dry eye symptoms. The published results reported effects on tear film osmolarity and on symptom measures such as redness and burning, alongside changes in participants’ blood fatty acid profiles confirming they had actually absorbed the oil.
Reading this fairly
These were relatively small trials in a specific population — people already experiencing dry eye — over three months, at a dose of about 2 g per day. That is considerably more oil than a shared slot in a 500 mg capsule blend can deliver. The evidence is real; whether it applies at the amount present in any given multi-ingredient product is a separate question the label usually does not answer.
Dry eye is also common, has several causes, and is treatable — an optometrist can identify what is driving it. See our eye health guide.
Safety considerations
Sea buckthorn has a good safety record, reflecting its history as a food.
- Anticoagulants. Some evidence suggests effects on platelet aggregation. Check with a pharmacist if you take blood thinners.
- Blood pressure medication. Possible additive effects at higher doses.
- Surgery. Stop concentrated oil supplements two weeks beforehand.
- Digestive effects. Loose stools are occasionally reported at higher oil doses.
- Pregnancy and breastfeeding. Culinary amounts are food; concentrated oil supplements have not been well studied.
The oil oxidises, so storage matters — cool, dark, tightly closed. A sea buckthorn oil that smells rancid should be discarded rather than finished.
How to read this guide
This page describes a plant and what has been studied about it. It is not advice about whether you personally should take anything. Dietary supplements are not medicines. They are not intended to diagnose, treat, cure or prevent any disease. Information on this page is for general education and does not replace advice from a doctor, pharmacist or other qualified health professional.
Talk to your doctor before starting any supplement if you take prescription medication, have a diagnosed condition, or are scheduled for surgery.