Calming for Extra Large Dogs is designed to support a calm demeanor in your pet during times that they may feel overstimulated or fearful. Our proprietary formula includes the naturally calming effects of L-Theanine, Thiamine and C3? (Colustrum Calming Complex). Calming supports a quiet state and provides a natural way to address stressful situations without a sedative like effect. Recommended for travel, boarding, trips to the veterinarian, fireworks, thunderstorms or any other situations that may cause your pet stress or anxiety. Calming is not a drug or sedative. It will not cause fatigue or a change in personality and, it may help your pet to be more calm and in situations where there is a lot of activity going on around them. Calming may begin to take effect in as little as 20 minutes and lasts for 4-6 hours. You can safely administer Calming XL on a day to day basis or only in times of high stress for your pet. This bite-sized chew has a delicious chicken flavor that dogs love and is designed to meet the needs of dogs over 75LBS.