Caffeine for Headache
Verdict: Published with Warning
Across 3 PubMed studies, the evidence for Caffeine in Headache grades Tier B — preliminary evidence. Effective, but with safety or population caveats.
B 🟡 B Preliminary Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.46
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
B · Published with Warning
Confidence
83%
Highly consistent evidence
Evidence level
E1
Cochrane high-quality SR/MA
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.463
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (3)L2 · primary research & systematic reviews
Caffeine as an analgesic adjuvant for acute pain in adults (Cochrane Review, Derry CJ)
Finding: Adding >=100mg caffeine gave a small but statistically significant benefit; ~5-10% more patients achieved good pain relief, NNT ~14 (high-quality evidence).
View on PubMed Sudden Caffeine Withdrawal Triggers Migraine - A Randomized Controlled Trial
Finding: Abrupt caffeine cessation provoked severe migraine attacks in 7 of 9 participants; trial terminated early for low recruitment, no formal p-value.
View on PubMed Caffeine for Headaches: Helpful or Harmful? A Brief Review of the Literature
Finding: Caffeine has dual role: effective adjuvant/treatment for several headache types, but abrupt cessation causes caffeine-withdrawal headache and overuse can drive medication-overuse headache.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Supportive
Caffeine is generally recognized as safe when used in cola-type beverages in accordance with good manufacturing practice. source↗
L4b EU EFSA
Cautious
Single doses of caffeine up to 200 mg (about 3 mg/kg bw) from all sources do not raise safety concerns for the general healthy adult population. The same amount of caffeine does not raise safety concerns when consumed less than two hours prior to intense physical exercise under normal environmental conditions. Caffeine intakes from all sources up to 400 mg per day consumed throughout the day do… source↗
L4d TW TFDA / 衛福部
Neutral
（一）每100毫升所含咖啡因高於或等於20毫克者，其咖啡因含量以每100毫升所含咖啡因之毫克數為標示方式……（二）每100毫升所含咖啡因低於20毫克者，其咖啡因含量以「20mg/100mL以下」標示之。（三）咖啡、茶及可可飲料，每100毫升所含咖啡因等於或低於2毫克者，得以標示「低咖啡因」替代前述「20mg/100mL以下」用語。 source↗
L5b Mayo Clinic
Cautious
Heavy daily caffeine use can lead to headaches. Generally, getting more than 400 milligrams of caffeine a day can cause headaches and irritability. source↗
L5c Cleveland Clinic
Cautious
larger amounts of caffeine, then it can have the opposite effect — bringing on a headache and increasing the frequency of headaches source↗
L5d Harvard Health
Cautious
Caffeine can be a trigger for migraine headaches. But it's complicated... For people who regularly drink coffee, missing an early morning cup -- or even just having your first cup later than usual -- can trigger a caffeine withdrawal headache. source↗
L5e Specialty Society (condition-mapped)
Cautious
Combination analgesics containing caffeine should be limited to 9 days per month to prevent medication overuse headache. source↗