MSM occurs naturally in the human body as a result of the food we eat. It is a normal component of fresh fruits, vegetables, seafood and meat. It has also been found in tea, coffee and chocolate. It has been detected in normal human urine. The amount of MSM present in the circulatory system of an adult human male is about 0.2 parts per million. Normal adult humans excrete from four to eleven milligrams of MSM per day in their urine. In vertebrates, the concentration of MSM decreases with age. Some research suggests that there is a minimum concentration of MSM that must be maintained in the body to preserve normal function and structure.

Experiments using MSM that contains radiolabled sulfur (35S) have shown that after ingestion, MSM gives up its sulfur to the essential amino acids methionine, cysteine and other serum proteins, eventually finding its way into the collagen of skin, joints and blood vessels. It is also incorporated into the keratin of hair and nails.

MSM is rated as one of the least toxic substances in biology. It is so inert and nontoxic that aqueous solutions can even be used as a blood diluent. In mice, no clinical changes were observed at oral doses of 2000 mg per kilogram of body weight. The lethal dose (LD50) of MSM for mice is over 20 grams per kilogram of body weight. Hundreds of patients have been treated at the Oregon Health Sciences University with oral MSM at levels above two grams daily for many years without serious toxicity.

Scientists don't yet know all the functions of MSM in the human body, but at the Oregon Health Sciences University the following conditions have responded well to supplemental MSM:

• Allergy Response to pollens and foods is sharply curtailed. Medication may be reduced or eliminated.
• Control of hyperacidity. Patients who have used antacids and histamine-receptor antagonists to control hyperacidity can employ MSM with excellent results.
• Relief from constipation. Patients with chronic constipation have had prompt and continuing relief with a daily supplement of MSM.