ProQuiet L-Tryptophan formula for dogs and cats, 60ct. A safe and gentle L-tryptophan formula that is helpful for maintaining a healthy nervous system and mental attitude. It has been tested and is safe and effective for use as directed by both dogs and cats. Safe enough to use daily or can be used as needed in stressful situations. Expiration date is 09-24. Thanks for looking and have a fine day.