PlainPill

Caffeine

People mainly take Caffeine for energy, focus, anxiety. Based on 761 first-hand reports and 680 meta-analyses & systematic reviews in the medical literature. Ranked #77 of 1,974 overall.

52
User score
Mixed
30% positive25% mixed13% negative32% unclear

Of reports that state an outcome, 44% are positive.

Clinical research
AStrong research base
680
meta-analyses
2,072
RCTs
37,272
papers

What Caffeine does, according to users

Of the people who reported each effect, the share who said it got better.

What the research says

Systematic reviews and meta-analyses from PubMed, with their published conclusions.

AStrong research base

3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.

Sleep Med Rev · 2023 · Meta-analysis / systematic review
The effect of caffeine on subsequent sleep: A systematic review and meta-analysis

Conclusion: To avoid reductions in total sleep time, coffee (107 mg per 250 mL) should be consumed at least 8.8 h prior to bedtime and a standard serve of pre-workout supplement (217.5 mg) should be consumed at least 13.2 h prior to bedtime. The results of the present study provide evidence-based guidance for the appropriate consumption of caffeine to mitigate the deleterious effects on sleep.

PubMed 36870101 ↗
JAMA · 2021 · Meta-analysis / systematic review
Acute Treatments for Episodic Migraine in Adults: A Systematic Review and Meta-analysis

Conclusion: There are several acute treatments for migraine, with varying strength of supporting evidence. Use of triptans, nonsteroidal anti-inflammatory drugs, acetaminophen, dihydroergotamine, calcitonin gene-related peptide antagonists, lasmiditan, and some nonpharmacologic treatments was associated with improved pain and function. The evidence for many other interventions, including opioids, was limited.

PubMed 34128998 ↗

Dosage people report

As stated by users — not a recommendation. Follow the label or your doctor.

100-150 mgdaily
200 mgmorning
100 mgas needed at headache onset
100 mgas needed
7000 mgdaily
300 mgdaily

Reported side effects

How often each side effect came up across all reports.

anxiety ×92jitteriness ×83insomnia ×38headache ×30fatigue ×29tolerance ×21heart palpitations ×4irritability ×3

What users say

Verbatim quotes, shortened only — each links to the original discussion.

Other options for energy

User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate