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Diphenhydramine and Tiredness: What Users Say

Brand names: Benadryl, Banophen, Benadryl Allergy, ZzzQuil, Diphen, Unisom SleepGels, Sominex, Benadryl Children's Allergy, Calm-Aid, Diphenydramine Quick Melt, Nytol, Unisom SleepMelts, Diphenhist, Diphendryl, Buckley's Bedtime, Hydramine Cough Syrup, Diphedryl, DPH, Diphenyl, Beldin, Hydramine, Hydramine Compound, Allermax, Dytuss, Dormin, Snooze Fast, Sominex Maximum Strength Caplet, Unisom SleepMinis, Unisom Liquid, ConRx Allergy, Dicopanol, Hyrexin, Bydramine, Diphen AF, Diphen Cough, Aler-Dryl, Allergia-C, Benahist-10, Benahist-50, Benoject-50, Diphenadryl, Genahist, Aller-G-Time, Sleep Tab II, Nytol QuickCaps, Trux-adryl, Valu-Dryl, Altaryl, Belix, Vicks QlearQuil Nighttime Allergy Relief, Silphen Cough, Diphenylin, Nytol Caplet, Compoz Nighttime Sleep Aid Sleepinal Help I Can't Sleep Twilite Banaril Aler-Tab Siladryl Allergy Sleep-ettes D Diphenmax Ben-Tann Dytan Vanamine PD Pharbedryl Histaprin Z-Sleep Aurodryl Children's Allergy Simply Sleep Complete Allergy Relief Miles Nervine Scot-Tussin Allergy Sleepwell 2-nite …show all brand names

Tiredness: mentioned by 24 users (4.4%)

Based on user experiences from 541 Diphenhydramine reviews, the following table shows the most commonly mentioned side effects.

All user comments are moderated by Drugs.com. Each review is verified for relevance and screened for inappropriate content. Side effects are user-reported and not clinically verified.

drowsiness 16.3%
nausea 4.6%
tiredness 4.4%
anxiety 4.3%
headaches 4.1%
restless leg syndrome 3.5%
dizziness 3.3%
restlessness 3.0%
sleepy 3.0%
dry mouth 2.8%

Reviews for Diphenhydramine

Commonly mentioned side effects
  • Deb...
  • September 5, 2020

Diphenhydramine for Insomnia "So awful! I never have an issue going to sleep, I just wake up too early. I took these as I had a long journey the next day. I was awake till 3:50 AM, really restless and buzzing! Felt like I was wired on coffee! Woke feeling exhausted and just terrible! They have the opposite effect - I’m throwing the rest in the bin and now have to drive for three hours feeling so awful!"

1 / 10
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69 Report
  • Luc...
  • October 3, 2018

Diphenhydramine for Insomnia "Diphenhydramine is a fantastic sleep aid, but you need to follow the dosage very, very carefully. I've struggled with insomnia since basically puberty, and a few years back I began taking ZzzQuil daily. I slowly grew a tolerance to it and increased my dosage eventually to 100 mg. One night I was so fed up with tossing and turning, I took another 100 mg (I was 19, OK?). An hour later I was watching the walls ripple like the surface of a pond, little black dots crawling up the walls here and there, and full-blown auditory hallucinations. (I.e., I heard orchestra music coming from the bathroom vent fan amidst its hum). I felt like my body was made of lead and was horribly lethargic. Still, after tossing and turning for hours, I eventually made it to sleep and felt as if I was awake the entire time. My roommate said I talked in my sleep the entire duration of my slumber, and my dreams were very vivid and unsettling. I felt like a train wreck the next day until I could finally go home and sleep."

8 / 10
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27 Report
  • Sle...
  • Taken for less than 1 month
  • January 13, 2023

Diphenhydramine for Insomnia "I took this for sleeplessness caused by anxiety. Personally, I found that Nytol knocked me out and kept me asleep, which was great because I needed the sleep, but the next morning, each time I would wake up and lose my balance, I felt faint and lethargic the whole next day after taking them, alongside aches and pains all along my body and heart palpitations."

4 / 10
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5 Report

Frequently asked questions

  • Ins...
  • Taken for 1 to 6 months
  • August 29, 2020

Diphenhydramine for Insomnia "Little (minuscule) help with insomnia, but bad, bad side effects. In the morning, very tired, groggy, not able to function normally. The morning feels like I am recovering from some illness. The worst sleep medicine ever!!!!"

1 / 10
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8 Report
  • Mad...
  • January 25, 2016

Diphenhydramine for Allergic Reactions "Allergy reaction to nuts. Started feeling swelling around mouth, throat... very scary, feel like I am stopping to breathe. This instant relief. Give it 10-15 minutes till it kicks in. WORKS WONDERS. BUT... you might need a good snooze after a good dose..."

10 / 10
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13 Report

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  • car...
  • Taken for less than 1 month
  • March 29, 2021

Diphenhydramine for Insomnia "When taking Nytol, I experienced a lot of drowsiness and got to sleep fairly quickly, however, it seems to 'wear off' and cause me to wake up in the middle of the night every time I have taken it. It also seems to cause tiredness in the day. I wouldn't take this again."

2 / 10
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6 Report
  • Woo...
  • Taken for 2 to 5 years
  • January 23, 2021

Diphenhydramine for Insomnia "I have used this for years. I’m peri-menopausal and my sleep routine is awful. I normally sleep 3-4 hours a night if I’m lucky, but with the help of this medication, I get 8-10 blissful hours. However, until about midday the following day, I feel tired and lethargic, but it’s worth it so my body gets some sleep... I only take it once a week. I’m going to try half a tablet twice a week and see how it goes!"

10 / 10
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6 Report

More FAQ

  • Woo...
  • Taken for 2 to 5 years
  • January 23, 2021

Diphenhydramine for Insomnia "I have used this for years. I’m peri-menopausal and my sleep routine is awful. I normally sleep 3-4 hours a night if I’m lucky, but with the help of this medication, I get 8-10 blissful hours. However, until about midday the following day, I feel tired and lethargic, but it’s worth it so my body gets some sleep... I only take it once a week. I’m going to try half a tablet twice a week and see how it goes!"

10 / 10
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6 Report
  • Toa...
  • Taken for less than 1 month
  • August 31, 2019

For Pruritus "I have 2nd degree sunburns, sun blisters all over my body, not a fun time. I haven't been able to sleep for a week. Burns are now starting to go away after 4 or 5 days of bad pain, and the itching is going crazy. Took two pills, within 15 minutes, the itching is gone. Within 30 minutes, I'm out cold. Wake up 3 hours later, make dinner, and in due time, ready to take the next dosage. Makes me feel extremely tired, so I go to bed, woke up 11 hours earlier. Such a lifesaver, just improved my sleep amount from 5 to 11 hours. Thank you, modern medicine!"

9 / 10
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7 Report
  • Nev...
  • February 3, 2023

Diphenhydramine for Insomnia "Tried this for the first time, and never again. I had the worst case of anxiety and restless leg syndrome that I’ve ever experienced in my life. Woke up tired from being up more than if I didn’t take it. On top of that, horrible dreams as well."

1 / 10
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3 Report
  • mir...
  • Taken for 2 to 5 years
  • May 4, 2016

For Insomnia "I split the tablets into 6 portions, and I sleep well, but I am very groggy the next morning and find it very hard to wake up. I stay sleepy and tired almost all day long. I feel very uncomfortable driving to work in the morning because I am so groggy."

2 / 10
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7 Report
  • PBU...
  • Taken for less than 1 month
  • February 21, 2021

Diphenhydramine for Insomnia "I do sleep at night, but wake up every few hours, so wanted to see if Nytol would help me sleep all night. On Friday, I took a tablet about an hour before bed, it didn't make any difference, but I was very tired in the morning and struggled to get going. Saturday, I tried again, the same thing, slept the night, but kept waking up, but this time in the morning, I was totally knocked out, couldn't move off the couch, and fell asleep around 10 AM for a while. Not good!"

1 / 10
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3 Report
  • for...
  • September 9, 2021

Diphenhydramine for Insomnia "I have chronic insomnia. I’m usually up until 4 AM, even then, sometimes I struggle. Thought with starting a brand new school soon, I’d try these as anxiety keeps me up too, and they have not worked whatsoever. In fact, they seem to have the opposite effect. My eyes do feel heavy, but when I try to sleep, I just can’t drift off, no matter what. Don’t recommend, I doubt I'll be trying these again."

1 / 10
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1 Report
  • che...
  • Taken for 1 to 6 months
  • March 31, 2021

For Insomnia "If you are not tired and you want some sleep aid that is gonna make you feel sleepy, take this. If you have severe insomnia like me and you have anxiety/other psychological problems that are the underlying causes of that insomnia, this probably is gonna do nothing for you. You're gonna feel the drowsiness and tiredness, but you'll be unable to sleep anyways."

5 / 10
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1 Report
  • Bri...
  • Taken for 1 to 6 months
  • June 11, 2019

Diphenhydramine for Insomnia "First time I took it, it did not work very well. I eventually fell asleep, but I do not think it had to do with the medicine. The second time I took it, I fell asleep rather quickly, but was very tired in the morning. I am trying it again for the third time to see if it will work well and to see if I will still be drowsy in the morning and/or if I will fall asleep quickly or at all."

6 / 10
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1 Report
  • Mar...
  • Taken for less than 1 month
  • August 16, 2018

For Insomnia "So when I first started using these, I had extreme insomnia, sometimes I would stay up until 5 AM. When I took the first set of Nyquil LiquiCaps (for sleep aid), I did feel sleepy, but not significantly enough to actually want to fall asleep. I took antihistamines daily before I resorted to diphenhydramine, so I may have grown a tolerance to it. But either way, this won’t work if you have been taking antihistamines for at least 2 months (at least in my case). Now all this does is make me uncomfortably drowsy, with heavy eyelids, but still the incapability to fall asleep. I recommend taking straight up melatonin."

2 / 10
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1 Report
  • Bob...
  • Taken for less than 1 month
  • June 14, 2022

Diphenhydramine for Insomnia "Complete waste of money. I'm a chronic insomniac. The side effects are terrible. Itchy, painful legs, tachycardia, and shakes in arms and unsteady legs. I need to go to the toilet more often, which is dangerous since I'm so shaky. I've not slept for 5 days solid while taking Nytol. This product should be taken off the market. Strongly advise to steer clear of it. I'm worse off now with tiredness and negative side effects."

1 / 10
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0 Report
  • Ann...
  • Taken for less than 1 month
  • January 5, 2022

Diphenhydramine for Insomnia "Tried these as I've been having restless nights and waking up every couple of hours. Made no difference and awake off and on throughout the night as usual. In the morning, felt awful. Woozy head and very tired. Won’t be using these again. Complete waste of money."

1 / 10
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  • Ste...
  • Taken for 1 to 6 months
  • July 19, 2017

For Insomnia "It is not a true sleep drug like prescription Z drugs or benzodiazepines. It can cause tiredness and thus help initiate sleep, but it's not very powerful in this regard. The effect is decent in those who have not used it much. Tolerance builds quickly. If you have not used it, it may work well, but after a few nights, it will likely lose most effect."

4 / 10
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1 Report
  • Ban...
  • February 12, 2016

Diphenhydramine for Insomnia "Takes a while to get to sleep, but once asleep, that's how I stay. However, I have found that it still affects me the next day... extremely groggy and exhausted. Not for me."

4 / 10
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24 Report
  • ean...
  • March 19, 2019

Diphenhydramine for Insomnia "This made me wake up every 2 hours all night, and I am always overly exhausted the next day, not worth it."

2 / 10
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9 Report
  • Anonymous
  • April 16, 2010

Diphenhydramine for Allergic Reactions "Made me fall asleep. Makes me way too tired."

4 / 10
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14 Report
  • Doe...
  • June 10, 2016

Diphenhydramine for Insomnia "I tried using it, took two pills (recommended dosage), and 20 minutes later, I'm tired. And it lasts for all of 30 minutes... can't fall asleep, then I'm wide awake again."

1 / 10
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11 Report
  • For...
  • July 7, 2017

Diphenhydramine for Insomnia "Did not seem to work. Felt tired the next day."

3 / 10
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0 Report

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Reviews may be edited to correct grammar/spelling or remove inappropriate content. Reviews appearing to come from parties with a vested interest are not published. This information is not intended to endorse any medication and should not replace the expertise and judgment of healthcare professionals.