Is Setting Multiple Alarms Bad for Your Sleep?

Setting multiple alarms or snoozing repeatedly before getting up does not clearly make waking harder than using a single alarm, according to a 2024 study in the Journal of Sleep Research — though it does measurably fragment the last stretch of sleep before you get up.

Is setting multiple alarms bad for you?

Less than the framing usually implies. Jenny Sundelin and colleagues at Stockholm University, publishing in the Journal of Sleep Research in 2024 (“Is snoozing losing? Why intermittent morning alarms are used and how they affect sleep, cognition, cortisol, and mood”), compared people who habitually snooze against a single-alarm wake-up in a lab setting. They measured cortisol, short-term memory and attention tasks, and self-reported grogginess right after waking. The snoozing group didn’t come out clearly worse on any of those. If you’ve assumed multiple alarms are quietly wrecking your mornings, that specific claim doesn’t hold up as cleanly as it’s usually stated.

How many alarms is too many?

The study doesn’t give a hard cutoff, because it wasn’t testing one. What it describes is typical behavior: habitual snoozers spent roughly 20 to 30 minutes cycling through alarms, usually two or three rounds, before getting up. That’s the range the null result on grogginess and cognition applies to — the paper says nothing about, say, an hour of stacked alarms, and it’s reasonable to assume the pattern doesn’t hold indefinitely.

Does snoozing make you more tired than one alarm?

Not by the measures this study used. But something real is happening during that window: the sleep between alarms is more broken up, with more brief arousals than an equivalent stretch of continuous sleep. The researchers just didn’t find that this fragmentation translated into worse waking performance or mood. That’s the genuinely odd part of the finding — the sleep is measurably worse, and the person isn’t. If you want more on why the moments right after waking feel foggy regardless of alarm count, see the DontSnooze piece on what’s happening during sleep inertia.

Why do people set multiple alarms in the first place?

Habit and self-distrust, mostly. Sundelin’s team found that among people who snooze, it’s not an occasional lapse — most of them do it on most or all mornings, and describe it as a preferred way to wake up gradually rather than something they’re trying to quit. That framing matters: alarm stacking isn’t usually an accident, it’s a routine people have built on purpose, even when they’d also say they wish they didn’t need it.

What’s a better alternative to alarm stacking?

Depends what the alarms are solving for. If it’s genuinely about easing into wakefulness, the fragmented-sleep finding suggests a single alarm set for your real get-up time, not your fantasy get-up time, would preserve more continuous sleep for the same net time in bed. If the real issue is that you don’t trust yourself to get up on the first ring — which is a different problem — more alarms won’t fix that; something that makes the first alarm final will. That’s closer to what’s covered in the DontSnooze explainer on sleep inertia and morning grogginess.

Would swapping alarm-stacking for a single commitment you can’t quietly dismiss change your mornings? Maybe — it depends on whether the real problem is distrust of the alarm or distrust of yourself to act on it. DontSnooze is built to test the second case specifically: someone you choose gets notified if you don’t confirm you’re up, which removes the option of a fourth snooze nobody’s watching.