Looking to support your immune system? Australia offers science-backed supplements regulated by the Therapeutic Goods Administration (TGA).

Below are 10 top immune boosters, each with specific benefits for immune health. All are part of the Mr. Vitamins Immune Booster collection, trusted by Australians year-round.

To check TGA approval, look for an AUST R, AUST L, or AUST L(A) number on the label.

Top 10 Supplements for Immune Support

1. Vitamin C
2. Vitamin D
3. Zinc
4. Probiotics
5. Elderberry
6. Echinacea
7. Aged Garlic Extract
8. Olive Leaf Extract
9. Medicinal Mushrooms
10. Manuka Honey 
    

Top 10 Natural Immune Support Supplements Summary 

1. Vitamin C 

Vitamin C is a powerful antioxidant and one of the most popular immune-supporting supplements. Since the body can't make it, getting enough through food or supplements is essential for immune health. Some key immunity benefits of vitamin C, according to a review in Nutrients Journal:

• • Supports immune cell function:

Vitamin C builds up in immune cells like phagocytes, helping them move toward and destroy harmful germs. It also helps remove old immune cells, protecting tissues during infections.

• • Strengthens overall immune defence:

Vitamin C supports many cellular functions involved in both innate (fast-acting) and adaptive (longer-term) immunity.  Deficiency weakens the immune system and makes people more likely to get infections. 

• • Reduces risk and severity of illness:

Getting 100-200 mg of vitamin C daily may reduce your chances of getting sick. If you do catch a cold, supplements can help you recover faster and ease symptoms.

Vitamin C supplements in Australia come as capsules, chewables, and powders. Some are non-acidic for gentler digestion. Taking a daily dose or a higher dose at the first cold sign can safely support your immune system.

2. Vitamin D 

Vitamin D, the "sunshine vitamin," is important for keeping the immune system in check. While known for bone support, it also controls how immune cells function. Many Australians don’t get enough, especially in winter, due to indoor lifestyles and screen time. Studies show Vitamin D: 

• • Regulates the immune system: 

Immune cells (B cells, T cells, and antigen-presenting cells) have special receptors for vitamin D and can activate it right where it's needed. This local activation allows vitamin D to fine-tune the immune response, helping immune cells communicate and coordinate better during an infection.

• • Lowers risk of infection: 

There is a strong link between low vitamin D levels and the risk of getting an infection. People who don't get enough vitamin D are more likely to get infections, colds and flus. 

• • Maintains immune defence readiness: 

Clinical studies show enough vitamin D may help protect against respiratory infections. Keeping vitamin D levels healthy (through smart sun exposure or supplements) helps your immune system fight off germs. 

Health experts recommend vitamin D3 supplements, especially in colder months, available as capsules, drops, or sprays. Vitamin D3 is one of the best basic immune health support supplements you can take because it helps immune cells work and keeps inflammation in check. 

3. Zinc 

Zinc is an important mineral that is necessary for a healthy immune system. It helps immune cells grow and work, such as neutrophils, natural killer cells, and T-lymphocytes. Getting enough zinc (through food or supplements) is very important for keeping your immune system strong because even a small deficiency in zinc can make it harder for your body to fight off infections. Researchers have found the following link between Zinc and immunity: 

1. • Supports immune cell function:

Zinc is essential for hundreds of enzymes and immune cell functions. It helps neutrophils, natural killer (NK) cells, T cells, and B cells grow and fight viruses and bacteria. Studies show zinc supplements-especially for older adults or those with low levels-can reduce infection risk, cell damage, and inflammation.

• • Protects skin and inner barriers: 

Zinc helps keep your skin and mucosal linings (like those in your nose, mouth, and lungs) strong. These are the body’s first line of defense against germs. Also playing a role in making new DNA in immune cells and works as an antioxidant, protecting cell membranes from damage.

• • Zinc deficiency weakens immunity:

Without enough zinc, the immune system doesn’t work as well. Defence of the immune system are decreased making you more susceptible to getting sick from many different viruses and bacteria. Studies show lozenges with Zince Gluconate taken at the first sign of a cold may help stop the virus from spreading in the throat, which shorten the length of the illness

Zinc citrate or zinc gluconate tablets are common supplements in Australia. The recommended daily amount isn't very high, but getting more zinc is a proven immune-boosting powerhouse when taken in the right amounts. Just remember not to take too much zinc for a long time, as very high doses can mess with other minerals. 

4. Probiotics 

Probiotics are "friendly" bacteria that help keep your gut healthy, where about 70% of your immune cells are found. Taking probiotic supplements (or eating probiotic-rich foods) helps maintain a balanced gut microbiome, which in turn trains and balances the immune system throughout the body.

Study reviews of probiotics links to a healthy immune systems have shown; 

• • Probiotics strengthen immune responses: 

Certain probiotic strains (like Lactobacillus and Bifidobacterium) help the immune system respond properly to pathogens without overreacting and harming tissues. They also strengthen the gut barrier, preventing unwanted microbes or toxins from entering the bloodstream and overloading the immune system.

• • Fewer Colds and Shorter Illnesses: 

Studies show that probiotics can reduce the risk, duration, and severity of common infections. A Cochrane review of randomized trials found that daily probiotic use led to fewer respiratory infections, and when illness did occur, it was typically shorter and milder. Milder illness means people are less likely to need antibiotics and are less likely to miss school or work.

Probiotic supplements with strains like Lactobacillus rhamnosus GG or Bifidobacterium lactis Bl-04 support respiratory and immune health. Available in high-dose capsules or powders (30-50 billion CFUs), they boost immunity by promoting a healthy gut-truly, “healthy gut, healthy immune system.”

5. Elderberry 

Elderberry (usually referring to black elderberry, Sambucus nigra) is a popular herbal remedy for colds and flu. The berries are packed with powerful plant compounds called flavonoids, especially anthocyanins, which may help fight viruses and reduce inflammation. Elderberry has a long history of traditional use in Europe for immunity. Now, modern science is starting to prove that it works against respiratory viruses. 

Studies have found the following links between Elderberry and boosting immunity:  

1. • Anti-Viral Action:

Elderberry contains compounds that block viruses from attaching to and entering cells. They also boost immune signals called cytokines, helping immune cells find and attack infected cells more effectively.

• • Speed up Immune Responses: 

Lab studies show elderberry extract interferes with viral proteins and increases cytokine production to ramp up the immune response, helping the immune system respond faster and clear infections early.

• • Clinical evidence of symptom relief:

A meta-analysis of randomised trials found elderberry supplements significantly reduce upper respiratory symptoms compared to placebo. One study showed flu patients recovered about four days faster with elderberry syrup. The meta-analysis confirmed shorter symptom duration, showing elderberry’s consistent benefits. Research suggests it works better against flu than cold viruses, though many say it helps colds too.

Elderberry supplements come as syrups, lozenges, gummies, liquid herbal extracts and capsules. They’re safe for families and popular for kids because they taste good. Elderberry is best used at the first sign of Cold or Flu & not necessarily taken as a long term preventative nor a convalescent tonic.

6. Echinacea 

Echinacea is an immune system "Modulator". It is able to boost the immune system when required - eg in cold / flu it upregulates the immune system. In Auto immune diseases where the immune system is over-active it is able to dampen the immune system. People take it to prevent colds and flu or reduce symptoms early on. Used for centuries by Indigenous North Americans, it’s now popular worldwide.

Research shows Echinacea supports the immune system by: 

• • Immune System Regulation

Echinacea helps your immune system by increasing the number and activity of immune cells like macrophages (which eat germs) and natural killer cells. It also helps the body release signals called cytokines that boost the immune response early on. Echinacea makes the immune system stronger when it needs to be but also stops it from overreacting. This helps protect you from getting sick and helps you recover faster if you do.

• • Fewer and Shorter Colds: 

A large meta-analysis published in The Lancet Infectious Diseases found that echinacea greatly lowers the number and length of colds. The analysis of 14 studies found that taking echinacea lowered the risk of getting a cold by 58%. If a cold did happen, it lasted an average of 1.4 days less. Overall evidence supports echinacea as a useful preventive measure. 

• • Decrease illness severity and complications: 

Studies have also shown Echinaceas immune strengthening effects may be linked to less complications and severity of illness when people get sick, lowering the need for antibiotics by stopping infections.    

In Australia, echinacea supplements comes as capsules, tinctures, and blends with herbs like garlic or elderberry. Throat sprays or drops deliver it directly to the respiratory lining. If you get colds often, echinacea is a handy natural remedy to keep you healthy.

7. Garlic (Extract from Aged Garlic) 

Garlic is not only a common cooking ingredient, but it is also a well-known immune-boosting plant. Allicin and other sulphur compounds in fresh garlic kill germs. Garlic is a popular home remedy for colds. For example, people used to make garlic soup to help with colds. Aged garlic extract is very popular as a supplement to support the immune system. This is because the ageing process concentrates beneficial compounds like S-allyl cysteine and lowers the harsh sulphur components, making it smell less and easy on the stomach. 

Below are some of the proven benefits of garlic for the immune system: 

• • Improving Immune Cells: 

Clinical studies have shown that aged garlic extract (AGE) makes important immune cells work better. In a randomised trial  by UF Food Science and Human Nutrition, healthy adults who took aged garlic had a lot more natural killer (NK) cells and T Cells. cells that were able to grow and become active. These are important immune cells that attack infected virus-infected cells and cancer cells to protect the body. 

• • Fewer and Milder Colds/Flu: 

Garlic has special compounds that can fight off germs and also work as antioxidants and reduce inflammation, helping your immune system in different ways. After 45 days on a garlic supplement, the immune cells in the garlic group vs placebo group reacted more strongly, indicating their immune system was primed to help to fight off infections better. The same study found that the garlic group had a lot fewer and less severe colds and flu than the placebo group. 

In Australia, odourless aged garlic extract capsules like Kyolic® offer immune benefits without garlic breath. Regular garlic capsules or a diet high in fresh garlic also help, but aged extract has the most immunity research. If you don’t mind garlic, it’s a great natural supplement to boost your immune system. 

8. Extract from Olive Leaves 

The leaves of the olive tree (Olea europaea) are used to make olive leaf extract. The Mediterranean region has long valued and used the extract for health. The leaf contains oleuropein and other polyphenols compounds which are very good at fighting inflammation, bacteria, and free radicals. Olive leaf extract is becoming more popular as an immune booster, often used to boost the immune system in general and as a way to shorten colds. 

Links between olive leaf extract and support for the immune system have been shown as;

• • Antioxidant & Anti-Inflammatory Support:

Olive leaf is rich in antioxidants that protect immune cells from damage during infection. It also reduces excess inflammation, helping the immune system fight germs without harming the body. This anti-inflammatory effect can ease symptoms like sore throat and stuffy nose. Additionally, oleuropein compound boosts phagocytosis, where immune cells engulf and destroy harmful microbes to fight infections.

• • Less time spent sick: 

While human research on olive leaf immunity is still emerging, one notable clinical trial in high school athletes found that those taking olive leaf extract had shorter colds. In the study, olive leaf supplementation did not significantly reduce the number of colds caught, but it did reduce the number of sick days by about 28%. 

In Australia, olive leaf extract is available as capsules, tablets, or tinctures. Choose supplements with a standardised oleuropein percentage to ensure the right dose of the active ingredient. Olive leaf extract is a natural immune booster rich in antioxidants and pairs well with traditional vitamins and herbs.

   

9.  Medicinal Mushrooms (Reishi & Others) 

For hundreds of years, Eastern medicine has used medicinal mushrooms to boost health and immunity. They've also become more popular in the West in the last few years. Types like Reishi (Ganoderma lucidum), Shiitake, Maitake, Chaga, and Cordyceps have special compounds called beta-glucans and triterpenes that can strongly affect the immune system. These mushrooms are thought to be immunomodulators, which means they can either boost a weak immune system or calm an overactive one to help keep things in balance. 

Medicinal mushrooms have been shown to boost the immune system by:

• • Broad Immune Enhancement: 

Mushrooms like Reishi boost immunity by improving both innate (first defence) and adaptive (learned) responses. They enhance macrophages (which eat pathogens), activate dendritic cells (which trigger immune reactions), and increase B and T cells. Mushroom compounds also support natural killer cells that destroy virus-infected cells and help produce cytokines, which coordinate immune cell communication. Medicinal mushrooms train the immune system to fight infections better and monitor abnormal cells.

• • Stress and Immunity:

Many medicinal mushrooms are also adaptogens, which means they help the body deal with stress. Stress can weaken the immune system, so mushrooms can help boost immunity by helping people deal with stress. Studies show mushroom extracts can boost immune markers; one found Reishi supplements increased T-cells and improved immune function in healthy adults.

Medicinal mushrooms come as capsules or powders to add to smoothies, coffee, or broth. Many products blend mushrooms like Reishi, Shiitake, Maitake, Cordyceps, and Turkey Tail for combined benefits. You can choose a single type or a mix to support your immune system.

 

10. Honey from Manuka 

Manuka honey is a unique type of honey that comes from bees that pollinate the Manuka bush (Leptospermum species) and is only found in Australia and New Zealand. It is known all over the world for its amazing health benefits and antimicrobial properties. Manuka honey helps the immune system in two ways: it fights pathogens directly and it helps the throat and lungs in general. Mauka Honey supports the immune system by:

• • Natural Antibacterial Power: 

Manuka honey is often called "nature's antibiotic" because it has broad-spectrum antibacterial and antimicrobial properties. Studies have shown it works against many types of bacteria and germs and has a high amount of a compound called MGO, along with other helpful substances, that can kill or stop the growth of bacteria-even some that don’t respond well to antibiotics.

• • Kills bacteria & viruses

Manuka honey helps get rid of bacteria, which makes it easier for your immune system to fight off an infection. It kills bacteria and viruses, and to some extent, fungi, so it can help with different types of infections or even just stop a second throat infection after a cold. 

• • Antioxidant and Soothing Effects: 

A spoonful of Manuka honey can soothe a cough or sore throat. Studies show it may be as effective-or more effective-than common cough syrups in reducing coughing in children. Honey coats the throat and stimulates saliva, which helps ease irritation. It also contains antioxidants and anti-inflammatory compounds that calm irritated tissues in the respiratory tract. Manuka honey may reduce oxidative stress during illness, supporting immune cells. Some research suggests it can also promote wound healing by activating nearby immune cells and triggering helpful immune signals.

Manuka honey is rated by its Methylgloxyl (MGO) rating; higher ratings indicate greater antimicrobial strength.

MGO Meaning: What You Need to Know | Complete Guide

MGO is an abbreviation for methylglyoxal, which is a naturally occurring organic compound. It is found in varying amounts in different types of honey, but manuka honey contains higher levels of MGO compared to other honey varieties.

The MGO rating indicates the concentration of MGO in manuka honey. It is measured in milligrams per kilogram (mg/kg) of honey. The MGO rating serves as a reliable indicator of the antibacterial strength of manuka honey. The higher the MGO rating, the more potent the honey is

When selecting manuka honey, it is important to consider your specific needs and the purpose for which you plan to use it. If you are looking for a milder option for daily consumption, MGO 100+ or MGO 250+ may be suitable. However, if you are seeking a more powerful antibacterial remedy, you may opt for MGO 400+ or MGO 550+.

For immune support, look for at least MGO 10+ or higher. Take a spoonful daily to stay healthy, mix it with warm water or tea, or put it directly on a sore throat (Just remember - honey should not be given to infants under 1 year old.)

Conclusion

Adding any of these top 10 immune-boosting supplements to your routine can help keep your immune system strong. Each one-whether a vitamin, mineral, herb, or natural extract-supports immunity in its own way. 

Many people find that combining a core daily nutrient like vitamin D or C with a herbal remedy at the first sign of illness works best. Always choose high-quality supplements and take the proper dose.

Supplements work best alongside healthy habits: good sleep, a balanced diet, regular exercise, and stress management. With the right support, your immune system can better protect you-even when others are getting sick. Stay healthy!

Resources 

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Aranow C. (2011). The Immune System and Vitamin D. J Investig Med, 59(6):881-6. PMID: 21527855. 

Gombart AF and others (2020). A look at how micronutrients and the immune system work together to lower the risk of infection. Nutrients, 12(1):236. A look at how zinc, vitamin D, and vitamin C affect the immune system. 

Hao Q et al. (2015). Probiotics to stop infections in the upper respiratory tract. Cochrane Database Syst Rev (2): CD006895. 

Hawkins J et al. (2019). A meta-analysis of RCTs shows that taking black elderberry (Sambucus nigra) can help with upper respiratory symptoms. **Complement Ther Med, 42:**361-365. PMID: 30670267. 

Shah SA and others (2007). A meta-analysis of echinacea for preventing and treating the common cold. Infect Dis, 7(7):473-480. PMID: 17597571. 

Percival SS. (2016). Aged garlic extract changes the way the immune system works in people. J Nutr, 146(2):433S-436S. PMID: 26764332. 

Somerville V and others (2019). A randomised controlled trial on the effect of olive leaf extract on upper respiratory illness in high school athletes. Nutrients, 11(2):358. 30744092 is the PMID. 

Lin Z and Wang X. (2019). Ganoderma (Lingzhi) has an immunomodulating effect, and this is how it works. **Adv Exp Med Biol, 1182:**1-37. 31777013. 

Johnston M et al. (2018). A look at the antibacterial properties of Manuka honey and its parts. AIMS Microbiol, 4(4)655- '. PMC6613335.