Formulated to lower the pH in your dog's urine to eliminate yellowing of grass & keep your lawn "spotless". Soft Chews are 1" soft, smoke-flavored treats. The active ingredient in Nutrivet Green Grass Soft Chews is dl-methionine, a ammonia-containing, essential amino acid. In the process of the body's natural metabolism of this amino acid, a slight acidification of urine can result. There are no detrimental health effects. Some feel that Yucca is actually more important in neutralizing the nitrogen that causes most of the damage to grass. This product has been sold for almost eight years with no reported adverse events with recommended use.