Superoxide dismutase as a therapeutic supplement

DEFINITION: Natural substance of the human body used as a supplement to treat specific health conditions.

• PRINCIPAL PROPOSED USES: Osteoarthritis, rheumatoid arthritis, interstitial cystitis
• OTHER PROPOSED USES: Anti-aging, radiation therapy support, wound healing, gout, sports injuries, antioxidant, paraquat poisoning, kidney transplant, cardiovascular benefits

Overview

In the body, dangerous naturally occurring substances called free radicals risk harming many tissues. The body deploys an antioxidant defense system to hold free radicals in check. Superoxide dismutase (SOD) is one of the most important elements of this system. It controls levels of a chemical called superoxide. The body manufactures superoxide to kill bacteria and for other uses, but excess levels of superoxide can injure healthy cells. SOD converts superoxide to hydrogen peroxide, and then another enzyme, catalase, neutralizes hydrogen peroxide.

Nutrients such as vitamin C and vitamin E also help neutralize free radicals. In the 1990s, such antioxidant supplements were widely promoted for preventing a variety of diseases, including cancer and heart disease. During this period, oral SOD became popular as a supplemental antioxidant. The results of several large studies tended to dash these hopes. Compared with ordinary antioxidants, SOD suffers from the additional disadvantages of being expensive and poorly absorbed when taken by mouth.

Requirements and Sources

SOD is not an essential nutrient, and it is not obtained through food.

Therapeutic Dosages

When SOD is taken orally, little to none of it is absorbed by the body. Some manufacturers market sublingual (under the tongue) forms of SOD that are purported to get around this problem. However, there does not appear to be any meaningful evidence that SOD can be absorbed any better this way.

Weak evidence hints that a form of SOD in which the substance is encapsulated in structures called liposomes may be absorbable. The optimum dose, if any, is not known.

Therapeutic Uses

Various internet sites promote SOD for a wide range of health problems, from preventing aging to enhancing sports performance. However, as noted above, oral SOD supplements may be ineffective because of poor absorption.

A bit of evidence hints that SOD injections may reduce scarring caused by radiation therapy and may also decrease symptoms of osteoarthritis. Double-blind, placebo-controlled trials performed on SOD in the twenty-first century show benefits for patients with osteoarthritis and rheumatoid arthritis. Patients with these conditions saw improvements in pain and inflammation. Patients with chronic bladder infections also experienced improvements in urgency and pain in another study. SOD applied directly to wounds may enhance wound healing, according to experiments in animals.

In test-tube, animal, and preliminary human studies, genetic manipulation has been used to increase SOD levels in the hope of finding anti-aging effects, but the results have been mixed.

Inhaled SOD appears to be useful for premature infants, helping to prevent a condition called respiratory distress syndrome. However, the only evidence for the benefits of any oral form of SOD is a study in animals involving the special liposome form of the supplement mentioned above. It found possible anti-inflammatory effects.

Other uses include controlling bladder inflammation, osteoarthritis, scleroderma, and urinary tract disorders. SOD has also been proposed to treat the pain and inflammation associated with gout and has been offered as a treatment for paraquat poisoning. Paraquat is an herbicide that produces harmful free radicals. In general, SOD has been proposed as a means of protection against free radicals, which can lead to chronic health conditions. Early research suggests SOD may help improve rejection rates among kidney transplant recipients. Finally, SOD may offer cardiovascular protection.

Safety Issues

Oral SOD is presumably safe, even as modern science makes it more absorbable. The safety of other forms of SOD (including the possibly absorbable encapsulated form) has not been established.

Bibliography

Carillon, Julie, et al. "Dietary Supplementation with a Superoxide Dismutase-Melon Concentrate Reduces Stress, Physical and Mental Fatigue in Healthy People: A Randomised, Double-Blind, Placebo-Controlled Trial." Nutrients, vol. 6, no. 6, 2014, pp. 2348-2359. MDPI, doi.org/10.3390/nu6062348. Accessed 11 Dec. 2025.

Davis, J. M., S. E. Richter, et al. "Long-Term Follow-Up of Premature Infants Treated with Prophylactic, Intratracheal Recombinant Human CuZn Superoxide Dismutase." Journal of Perinatology, vol. 4, 2000, pp. 213-216.

Dong, Liang, et al. "Oral Delivery of a Highly Stable Superoxide Dismutase as a Skin Aging Inhibitor." Biomedicine & Pharmacotherapy, vol. 164, 2023. ScienceDirect, doi.org/10.1016/j.biopha.2023.114878. Accessed 11 Dec. 2025.

Rosa, Arianna Carolina, et al. "Superoxide Dismutase Administration: A Review of Proposed Human Uses." Molecules, vol. 26, no. 7, 2021, p. 1844, doi:10.3390/molecules26071844. Accessed 11 Dec. 2025.

"Superoxide Dismutase." Memorial Sloan Kettering Cancer Center, 24 July 2023, www.mskcc.org/cancer-care/integrative-medicine/herbs/superoxide-dismutase. Accessed 11 Dec. 2025.

"Superoxide Dismutase." RxList, www.rxlist.com/supplements/superoxide_dismutase.htm. Accessed 11 Dec. 2025.

Younus, H. "Therapeutic Potentials of Superoxide Dismutase." International Journal of Health Sciences, vol. 12, no. 3, 2018, pp. 88-93.