Caffeine
Also known as: Caffeine anhydrous
Caffeine is a widely used stimulant commonly explored for alertness and focus. Sensitivity varies a lot between people, and late-day intake can affect sleep. It can raise heart rate and blood pressure in some people.
Snapshot
Evidence level is outcome-specific; a supplement can have stronger evidence for one use and limited evidence for another.
What this page can tell you: Commonly discussed timing, food notes, caution categories, and an honest note on how much source review this entry still needs.
What it cannot: Whether this is appropriate for you personally, or that it treats, prevents, or cures any condition. Informational only — discuss with a clinician or pharmacist.
🕒 Timing
When: Morning, Midday
Food: With or without food
Effects peak around 30-60 minutes and can last several hours, so it is commonly kept to earlier in the day (often none within about 8-10 hours of bedtime) to protect sleep. Tolerance builds with regular daily use.
💊 Common use range
50–200 mg
Many health bodies cite up to ~400 mg/day for healthy adults; individual tolerance varies. Pregnancy limits are lower — talk to a professional.
Ranges are informational, not a recommended dose. Talk to a professional about what is right for you.
🤔 Worth considering?
Evidence vs. effort: Moderate evidence relative to burden
Widely used and generally tolerated by healthy adults within common limits; sensitivity varies a lot between people. Pure or highly concentrated caffeine products can be dangerous. Pregnancy, breastfeeding, and certain conditions are reasons to check with a professional.
A general summary, not a recommendation. Whether something fits your situation is worth discussing with a healthcare professional.
⚠️ Commonly noted interactions (supplements)
None listed.
Often about absorption or timing rather than danger — separating doses is common. This list is not exhaustive.
🧭 Baseline caution
General caution for ordinary, common use — before accounting for your specific dose, medications, health history, or procedures.
No general caution factors flagged for ordinary use. See context alerts below for situations that may still apply to you.
Caution level is an informational summary of commonly discussed caution categories and doses — not a safety rating, approval, or medical advice. Low caution does not mean safe for you.
🔎 Context alerts to review
Context alerts may matter depending on your dose, medications, health history, or procedure plans — they do not mean the supplement is generally risky at ordinary use.
Medications
- Stimulant — timing and heart-rate considerations
- Higher caution if you take stimulant medication
- Higher caution if you take blood-pressure medication
- Serotonergic (SSRI/SNRI) interaction
- MAOI medication interaction
🩺 Medication caution categories
- Stimulants — Combining with stimulant medication can add up on heart rate, blood pressure, sleep, and anxiety.
- Blood pressure medication — Some items can nudge blood pressure on their own, so combined with blood-pressure medication the effects could add up. Discuss monitoring with your clinician.
- Antidepressants (SSRIs/SNRIs) — The concern is a compounding effect on serotonin, or an interaction with the medicine — a conversation for the prescriber, not something to start on your own.
- MAOIs — MAOIs have serious food and supplement interactions. Don't combine anything without explicit guidance from the prescriber.
🏥 Surgery & procedure caution
Fasting before surgery usually means no caffeine; abrupt cessation can cause headaches. Follow your care team's instructions.
If you have a procedure scheduled, bring your full supplement list to your surgical and anesthesia team. Do not stop prescribed medication unless your clinician tells you to. Do not start or stop supplements based only on this app.
✅ Quality checklist
- Prefer products with third-party testing or a certificate of analysis (COA).
- Check the label for the exact form and the elemental or active amount per serving.
🧩 Commonly paired with
🔁 Alternatives
🗣️ Questions for a professional
- Is Caffeine appropriate alongside my medications and health history?
- Is there a test or check that would tell us whether I actually need it?
🔬 Evidence snapshot
A stimulant. The FDA states that for healthy adults about 400 mg/day is an amount not generally associated with dangerous negative effects, while emphasizing wide individual variation.
🧪 Forms & quality
Needs evidence review — no source-reviewed information yet. We only show dose and monitoring details after they have been checked against reputable sources.
See the supplement glossary for what form names like "L-", chelated, or standardized extract mean.
📏 Dose & monitoring
No formal upper limit, but the FDA cites about 400 mg/day (roughly two to three 12-oz cups of coffee) for healthy adults as not generally associated with negative effects. What is too much varies by body weight, medications, conditions, and sensitivity.
Evidence vs. burden: Moderate evidence relative to burden
😐 Commonly reported side effects
- Jitteriness, increased heart rate, anxiety, sleep disruption, dependence/withdrawal
Non-exhaustive and individual.
🔄 Cycling & breaks
Some people periodically reduce intake to manage tolerance.
📅 Daily use notes
Watch total daily intake across coffee, tea, and supplements. Avoid late-day use for better sleep.
📋 Source review status
Source-reviewed — last reviewed 2026-07-02
Placeholder — verify pregnancy and interaction wording.
📚 References
- FDA - Spilling the Beans: How Much Caffeine is Too Much?FDA — Verified ~400 mg/day figure and individual-variation and concentrated-product cautions (FDA consumer update).
Verified against the source shown. See the research-status page for how review works.
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