Many people turn to over-the-counter sleeping tablets, believing them to be a harmless solution for insomnia.
But experts are now raising alarms, warning that thousands may be unknowingly dependent on these medications, taking them for months or even years.
The Risks Behind Diphenhydramine-Based Sleep Aids
Popular sleep aids like Nytol One-a-Night, Boots Sleepeaze, and Panadol Night contain diphenhydramine, an antihistamine known for its sedative effects.
Because they’re available without a prescription, many assume they’re a safer alternative to stronger, prescription-only medications like benzodiazepines.
However, growing research suggests otherwise. Studies have linked long-term use of diphenhydramine to severe health risks, including addiction, seizures, and even coma.
In one shocking case, a 32-year-old man named Grant Holding, who relied on Nytol after struggling to get his prescribed medication, was found dead in his home.
Toxicology reports revealed dangerous levels of diphenhydramine in his system—amounts known to be potentially fatal.
Sleep Aids and the Dementia Connection
Perhaps even more alarming, studies suggest these medications could increase the risk of dementia.
One major study tracked nearly 3,500 older adults and found that those who had taken high levels of diphenhydramine over ten years had a 54% higher chance of developing dementia.
More recent research involving almost a million British patients found that certain anticholinergic drugs, including diphenhydramine, were associated with an 18% higher risk of dementia, with men being more at risk than women.
The Scary Side Effects People Are Experiencing
Beyond the long-term risks, many users have reported terrifying short-term effects.
People who took these tablets for extended periods have shared their experiences online, describing disturbing hallucinations.
One person wrote:
“At first, one pill did nothing. Then I started taking two, then three.
One night, I took five. I had horrifying dreams about spiders crawling around my room.
My roommate told me I was mumbling nonsense, but I don’t remember any of it.”
Another admitted to taking the medication every day, saying:
“It became a crippling addiction. I haven’t seen the spiders, but I’ve heard that’s a common thing.
I just feel like I’m trapped in a dream where there is no tomorrow.”
Some even reported experiencing terrifying visual distortions, like feeling underwater or seeing hallucinations of fairies and spirals.
Why These Pills Stop Working Over Time
Experts warn that diphenhydramine can quickly lose effectiveness. Dr. David Rapoport, a professor of pulmonary and sleep medicine at Mount Sinai in New York, explains:
“The body adapts to it within just two weeks, meaning users have to take higher and higher doses to get the same effect—leading to even greater risks.”
While mild side effects like dizziness and dry mouth are common, more severe reactions can include seizures, difficulty controlling movements, and dangerously fast heartbeats.
Time to Rethink Your Sleep Routine
Health experts strongly advise against long-term use of diphenhydramine-based sleep aids.
Harvard-trained immunity and diet expert Dr. Amy Shah emphasizes:
“I know these medications are over-the-counter, but we know so much more now.
You should not be using them regularly. There are safer alternatives.”
For those struggling with sleep, newer antihistamines like Zirtec, Allegra (Allevia in the UK), and Clarityn may be better options, as they don’t affect the brain as much.
The Bottom Line
If you’ve been relying on over-the-counter sleeping pills for a long time, it might be time to reconsider.
Not only could they be harming your brain and body, but they might not even be helping you sleep anymore.
Talking to a doctor about safer alternatives or natural sleep solutions could be the best step toward healthier rest.