Antioxidants
Browse antioxidant supplements: vitamin C, vitamin E, selenium, zinc, CoQ10, astaxanthin and plant extracts. We explain which forms are absorbed well, what a sensible daily amount looks like and who each one suits.Read more →
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How antioxidant supplements work and which one fits you
Antioxidants help protect cells against oxidative stress. Oxidative stress is the wear that happens when unstable molecules, called free radicals, outnumber your body's own defences. Your body builds part of that defence itself. The rest comes from food: berries, nuts, olive oil, green tea and vegetables. A supplement adds a concentrated amount of one or a few of these compounds, in a dose you can read on the label.
Different antioxidants do different jobs
Vitamin C is water-soluble and works in the watery part of the cell. You will find the various vitamin C options in their own collection. Vitamin E is fat-soluble and sits in the fatty membrane around the cell. Selenium, zinc, copper and manganese are not antioxidants themselves. They are building blocks for your body's own antioxidant enzymes, so a modest daily amount is enough. All of these carry an approved European claim: they contribute to the protection of cells from oxidative stress. Plant compounds such as resveratrol, quercetin and green tea polyphenols have no approved claim, and we do not invent one for them.
The form decides how much reaches your cells
Absorption often matters more than the number on the front of the pack. Coenzyme Q10 is fat-soluble, so an oil-based softgel is absorbed far better than dry powder pressed into a capsule.
- Fat-soluble: vitamin E, CoQ10, astaxanthin, lutein. Take them with a meal that contains some fat.
- Water-soluble: vitamin C and most polyphenols. Splitting the dose across the day works better than one large serving.
- Buffered vitamin C (magnesium or sodium ascorbate) is gentler on an empty stomach than plain ascorbic acid.
- Liposomal: the nutrient is wrapped in a tiny fat layer so the body absorbs more of it. Useful, and usually dearer per gram.
Dose logic runs the other way from what the packaging suggests. Astaxanthin from algae is used in single milligrams, not hundreds. Selenium works at microgram level. A high number is a sign of marketing more often than of a better product.
How we choose the antioxidants we stock
We look at three things: the form, the dose and whether a combination makes sense. For CoQ10 we prefer oil-based softgels, because a dry powder is poorly absorbed. For selenium we prefer selenomethionine in amounts close to daily needs, since more is not better here. We leave out products that hide a dozen extracts in a blend without naming the amounts. We only repeat claims the European food safety authority (EFSA) has approved. Every product passes our compliance team, and independent labs spot-check batches. Read how we select brands and products.
Who these supplements suit, and what to expect
An antioxidant is not something you feel. There is no rush of energy and no day-one difference, which is exactly why the dose and the form deserve your attention instead. They make most sense when there is a genuine gap: little fruit and veg on your plate, a plant-based diet low in selenium, or an older body that makes less CoQ10 than it used to. If you already eat a varied diet, a single targeted product usually beats a stack of five. And more is not automatically safer: several antioxidants have a clear ceiling, which we set out in the questions below.
Frequently asked questions
Antioxidants are compounds that help protect your cells from oxidative stress. Oxidative stress is the damage that builds up when free radicals, unstable molecules produced during normal metabolism and by smoking, sunlight and pollution, outweigh your body's defences. Some antioxidants come from food, such as vitamin C and vitamin E. Others are made inside the body using minerals like selenium and zinc as building blocks. A supplement simply supplies a measured amount of one of these compounds.
Often not. A varied diet with vegetables, fruit, nuts, olive oil and oily fish already delivers a broad mix of antioxidants, and the UK guidance is to get nutrients from food where possible. A supplement is useful when there is a real gap: few vegetables in your week, a plant-based diet low in selenium, or a period when your eating is simply not consistent. In that case one targeted product is more sensible than a stack of several.
Start from what your diet misses, then pick the form that is absorbed well.
| Antioxidant | Form we prefer | Suits |
|---|---|---|
| Vitamin C | Buffered ascorbate | Sensitive stomachs |
| Vitamin E | Mixed tocopherols | Food-like profile |
| CoQ10 | Oil softgel, ubiquinol | Adults over 40 |
| Selenium | Selenomethionine | Low fish or nut intake |
| Astaxanthin | Algae oil softgel | Plant-source preference |
| Lutein | Free lutein with zeaxanthin | Long screen days |
Timing follows solubility. Fat-soluble antioxidants such as vitamin E, CoQ10, astaxanthin and lutein need some fat to be absorbed, so take them with your main meal rather than with black coffee. Water-soluble ones such as vitamin C are cleared quickly, so two smaller servings spread across the day keep levels steadier than one large dose. If plain ascorbic acid gives you a rumbling stomach, take it with food or switch to a buffered form.
Each antioxidant has its own ceiling for supplement use. The UK guidance below refers to the amount from supplements, on top of what you get from food.
| Nutrient | Daily amount from supplements |
|---|---|
| Vitamin C | Under 1,000 mg |
| Vitamin E | 540 mg (800 IU) or less |
| Selenium | 350 mcg or less |
| Zinc | No more than 25 mg |
| Beta-carotene | No more than 7 mg |
You will not feel it working, and that is normal. Antioxidants act at cell level, not on your mood or energy within an hour. Blood levels of vitamin C rise within days, while fat-soluble compounds such as CoQ10 and astaxanthin build up over roughly two to three weeks of consistent daily use. Judge a product by its form and dose, not by a sensation. If you are looking for something noticeable, an antioxidant is the wrong category.
Yes, three points are worth knowing. Beta-carotene supplements are not advised for people who smoke or who have been heavily exposed to asbestos, and the UK limit is 7 mg a day. Zinc above 25 mg a day from supplements reduces copper absorption over time. And selenium has a narrow window: a couple of Brazil nuts already cover the day, so a 200 mcg tablet on top adds up faster than people expect.
This comes up often among athletes. Exercise itself creates a short burst of oxidative stress, and that signal is part of how muscles adapt. Research suggests that very high daily doses of vitamin C and vitamin E, taken right around training for months, may dampen some of that adaptation. Normal intakes from food and modest supplement doses are not the issue. If you train seriously, keep large single doses away from your session window and take them with another meal.
