what in benadryl makes you sleepy

Benadryl makes people sleepy because it contains an antihistamine called diphenhydramine, which is known as a drowsy or sedating antihistamine. Diphenhydramine blocks the effects of histamine in the brain, which reduces symptoms such as a runny nose or skin rashes. Histamine is also involved in keeping people awake during the day, so when Benadryl blocks the effect of histamine, it leads to sleepiness. Diphenhydramine affects the bodys natural sleep-wake cycle, making it easier to fall asleep. However, it can cause side effects such as nervousness, dry nose, mouth, and throat, dizziness, headache, nausea, and loss of appetite. In addition, studies have not found evidence that it improves sleep quality, and it may even decrease the quality of a persons sleep. Therefore, it is important to use Benadryl as a sleep aid only for short-term relief and not rely on it for chronic insomnia.