MSM (Methylsulfonylmethane) is an organic sulfur-containing compound widely available as a dietary supplement. Recently, liquid formulations have been marketed for direct ocular application, suggesting benefits for various eye conditions. Applying this compound directly onto the delicate surfaces of the eye raises significant questions about its safety and effectiveness. Examining the chemical nature of MSM and the scientific evidence surrounding its ophthalmic use is necessary due to the rapid growth of interest in these drops.
The Chemical Identity of MSM
Methylsulfonylmethane is an organosulfur compound with the chemical formula (CH₃)₂SO₂. It is also known as dimethyl sulfone or methyl sulfone. MSM is a metabolite of dimethyl sulfoxide (DMSO), a well-known solvent. This compound is a white, crystalline solid containing a sulfonyl functional group. MSM occurs naturally in small amounts in some primitive plants, foods, and beverages. Although it provides sulfur, this element is already abundantly available in the diet through sulfur-containing amino acids found in protein.
Ocular Health Claims Associated with MSM
Consumers are interested in placing liquid MSM directly into their eyes due to various marketed and anecdotal claims. These claims suggest MSM can address several common eye complaints. A frequently cited benefit is its purported anti-inflammatory capacity, which advocates suggest can help alleviate symptoms of dry eye syndrome or inflammation-related discomfort.
MSM is also claimed to function as an antioxidant, potentially protecting the retina from free radical damage. Proponents suggest MSM can increase the permeability of cell membranes, including those in the cornea, theoretically allowing for better nutrient absorption. These ideas have led to its promotional use for conditions like cataracts, eye floaters, and reducing intraocular pressure. However, these remain unproven claims lacking consistent scientific studies.
Assessing the Safety of Liquid MSM for Eye Use
The safety profile of liquid MSM for direct eye use is highly questionable, primarily due to the risk of contamination and lack of standardization. Ophthalmic solutions must meet stringent requirements for sterility and purity to prevent serious infections. Non-ophthalmic grade MSM or homemade solutions pose a significant risk of containing harmful bacteria, fungi, or other microbes.
Regulatory testing recently found liquid MSM eye drops contaminated with various dangerous microbes, including Bacillus species, Exophiala species, and Pseudomonas species. Using contaminated drops can result in minor irritation or severe, vision-threatening infections that could progress to permanent vision loss or systemic infection.
The concentration and pH level of the solution are also critical safety factors. The human eye is sensitive to solutions that are too acidic or too alkaline, which can cause severe irritation, burning, or damage to the corneal surface. Highly concentrated MSM solutions can also lead to adverse effects like temporary stinging, redness, or blurred vision.
Ingestion of MSM has also been associated with adverse ocular events in case studies. One report described bilateral acute angle closure glaucoma following the ingestion of a dietary supplement containing MSM. This condition is a sudden, severe rise in intraocular pressure that can cause permanent vision damage, suggesting a potential systemic risk.
Regulatory Status and Professional Guidance
Liquid MSM products marketed as eye drops are generally considered unapproved drugs by major regulatory agencies. The U.S. Food and Drug Administration (FDA) has stated there are no legally marketed ophthalmic drugs containing MSM as an active ingredient. The regulatory pathway for dietary supplements (under which MSM is typically sold for oral use) differs completely from the rigorous approval process required for sterile, topical eye medication.
The FDA has issued public warnings advising consumers to immediately stop using specific brands of liquid MSM eye drops due to identified microbial contamination. These warnings underscore that the products are illegally marketed and do not meet the required sterility standards for safe eye application.
Given these significant risks, eye care professionals strongly advise against placing any non-prescribed or non-approved substance into the eyes. Individuals considering MSM for eye conditions should consult with an ophthalmologist or optometrist before use. Professional guidance is important for those with existing eye diseases, as using unapproved drops could interfere with prescribed treatments or exacerbate underlying issues.