5-HTP 100mg are a natural dietary supplement that contains 5-Hydroxytryptophan, a compound that is converted into serotonin in the brain. Serotonin is a neurotransmitter that plays a key role in regulating mood, appetite, and sleep. By taking a 100mg dose of 5-HTP, users may experience an increase in serotonin levels, which can lead to improved mood, reduced anxiety, and better sleep quality.