The Top 9 Supplements to Support Your Immune System

There is strong evidence that Zinc improves acute respiratory tract infection risk, with Examine.com rating the evidence as grade A. Zinc as a supplement is a mineral derived from dietary (also synthesised), commonly taken as capsule or lozenge. Studies typically use 10–40mg.

Zinc is an essential mineral involved in a wide range of processes in the body, from immune function and wound healing to hormone production and DNA repair. It is known to reduce the duration of the common cold when taken at the onset of symptoms, and it can support testosterone levels and fertility in men. It is also used to support skin health and reduce acne. It is found in meat, shellfish, and legumes, and is available as a capsule or lozenge. Taking it with food can reduce the nausea that sometimes occurs on an empty stomach.

There is good evidence that Elderberry improves upper respiratory tract infection symptoms, with Examine.com rating the evidence as grade B. Elderberry as a supplement is a berry extract derived from plant berry, commonly taken as syrup or capsule or gummy. Studies typically use 500–1500mg (extract).

Elderberry is a dark purple berry from the elder tree, long used in European folk medicine. It is known to reduce the duration and severity of colds and flu, and it can support immune function more broadly. It works best when taken at the first sign of illness rather than as a preventative. It is most commonly available as a syrup, gummy, or capsule, and the syrup form has the longest history of traditional use.

There is good evidence that Honey improves upper respiratory tract infection symptoms, with Examine.com rating the evidence as grade B. Honey as a supplement is a natural food derived from bee-produced, commonly taken as liquid (raw or manuka). Studies typically use 1–2 teaspoons as needed.

Honey is a natural sweetener produced by bees from flower nectar, and has been used medicinally for thousands of years. It is known to soothe sore throats and reduce the frequency and severity of coughing, particularly at night. It also has mild antimicrobial properties. Raw and Manuka honey are the most researched varieties for health purposes. It is not a supplement in the conventional sense — it is taken directly by the spoonful or stirred into a warm drink.

There is good evidence that Colostrum improves upper respiratory tract infection risk, with Examine.com rating the evidence as grade B. Colostrum as a supplement is a dairy-derived derived from bovine (cow), commonly taken as capsule or powder. Studies typically use 20–60g.

Colostrum is the first milk produced by mammals in the days after giving birth. Bovine colostrum — sourced from cows — is rich in immunoglobulins, growth factors, and other bioactive compounds. It is known to support immune function and gut health, and it can help to reduce the frequency of upper respiratory infections. It is also used by athletes to support muscle recovery and reduce gut permeability caused by intense exercise. It is available as a capsule or powder.

There is good evidence that Vitamin D improves upper respiratory tract infection risk, with Examine.com rating the evidence as grade B. Vitamin D as a supplement is a vitamin derived from synthetic (lanolin or lichen), commonly taken as softgel or tablet or drops. Studies typically use 1,000–4,000 IU.

Vitamin D is a fat-soluble vitamin the body produces when skin is exposed to sunlight. Most people in northern climates or who spend limited time outdoors have low levels, which affects immune function, bone strength, and mood. Research shows strong evidence across a wide range of outcomes — including reduced infection risk, improved bone mineral density, and reduced symptoms of depression and anxiety. It is best taken as a softgel or drop with a meal containing fat, which is needed for absorption.

There is good evidence that Vitamin C improves upper respiratory tract infection symptoms, with Examine.com rating the evidence as grade B. Vitamin C as a supplement is a vitamin derived from dietary (also synthesised), commonly taken as tablet or capsule or powder. Studies typically use 250–1000mg.

Vitamin C is a water-soluble vitamin and antioxidant that is essential for many processes in the body. It is well known for its role in immune function and is known to reduce the duration of the common cold when taken regularly. It also plays a central role in collagen production, which supports skin, joints, and connective tissue. It can support iron absorption from plant-based foods and may help to reduce exercise-related muscle soreness. It is found in citrus fruits, peppers, and berries, and is available as a tablet, capsule, or powder.

There is good evidence that Echinacea improves common cold symptoms, with Examine.com rating the evidence as grade B. Echinacea as a supplement is a herb derived from plant (root / aerial parts), commonly taken as capsule or tincture. Studies typically use 300–500mg (3x daily at onset).

Echinacea is a flowering plant native to North America that has been used in herbal medicine for centuries. It is known to support immune function and can reduce the duration and severity of the common cold when taken at the first sign of symptoms. It is most effective when used short-term at the onset of illness rather than as a long-term daily supplement. It is available as a capsule, tablet, or tincture, with preparations made from the root generally considered more potent.

There is good evidence that Beta-glucans improves upper respiratory tract infection symptoms, with Examine.com rating the evidence as grade B. Beta-glucans as a supplement is a dietary fibre derived from oat / barley / mushroom, commonly taken as capsule or powder. Studies typically use 3–6g (oat); 250–500mg (mushroom).

Beta-glucans are soluble fibres found naturally in oats, barley, and certain mushrooms. They are known to lower LDL cholesterol and support healthy blood sugar levels after meals. They also have well-established immune-supporting properties, particularly the beta-glucans derived from yeast and medicinal mushrooms such as reishi and shiitake. They are available as capsules or powders and can also be obtained in meaningful amounts from a bowl of porridge.

There is good evidence that Garlic improves upper respiratory tract infection symptoms, with Examine.com rating the evidence as grade B. Garlic as a supplement is a herb derived from plant bulb, commonly taken as capsule or tablet. Studies typically use 600–1200mg (aged garlic extract).

Garlic is a bulb vegetable with a long history of use in both cooking and traditional medicine. It is known to support cardiovascular health by reducing blood pressure and LDL cholesterol levels. It can also support immune function and may help to reduce the frequency of colds. The active compound, allicin, is released when garlic is crushed or chopped. Supplements are available as capsules or tablets, often in aged or odourless forms that are easier to take daily.