# I can't sleep when I'm supposed to and I get tired when I'm really not supposed to

**URL:** <https://boards.straightdope.com/t/i-cant-sleep-when-im-supposed-to-and-i-get-tired-when-im-really-not-supposed-to/531836>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [March 9, 2010, 9:57am UTC](https://boards.straightdope.com/t/i-cant-sleep-when-im-supposed-to-and-i-get-tired-when-im-really-not-supposed-to/531836 "2010-03-09T09:57:06Z")\
**Posts on this page:** 1\
**Page:** 2

<div class="post-metadata">

**Author:** ![GilaB](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@GilaB](https://boards.straightdope.com/u/GilaB)\
**Post date:** [March 11, 2010, 7:49pm UTC](https://boards.straightdope.com/t/i-cant-sleep-when-im-supposed-to-and-i-get-tired-when-im-really-not-supposed-to/531836/21 "2010-03-11T19:49:34Z")

</div>

The PM part of Tylenol PM is just diphenhydramine, aka benadryl. You can get that pretty cheaply in generic form. That said, I would really not recommend long-term use; you can get resistant to lower doses, then keep upping it, which isn’t good for you over the long term. I definitely wouldn’t take Tylenol PM long-term, as acetaminophen/paracetamol (Tylenol) is damaging to the liver when taken for a long time.

[Previous page](https://boards.straightdope.com/t/i-cant-sleep-when-im-supposed-to-and-i-get-tired-when-im-really-not-supposed-to/531836.md?page=1)