How much caffeine is in Oolong Tea (8oz cup)?
中文：乌龙茶（8 盎司）
Caffeine content
45 mg
Typical range: 30–65 mg
per 8 fl oz (237 ml)
About this drink
Oolong sits between green and black tea — caffeine roughly 45 mg per cup. Tieguanyin and Dahongpao are popular varieties with mild caffeine but rich flavor.
Ingredients: Partially-oxidized tea leaves, hot water
When will it clear your system?
45 mg metabolizes cleanly. A traditional Chinese tea afternoon (3-4 cups over 2 hours) keeps you in safe territory.
Based on caffeine's 5-hour half-life, a Oolong Tea (8oz cup) consumed at 2:00 PM drops below the sleep-safe threshold (~20 mg) by approximately 19:51 the same evening.
Where this fits in a daily limit
That's about 23% of the 200 mg pregnancy guideline and 11% of the 400 mg general adult daily limit — comfortably moderate.
See our pregnancy caffeine guide or half-life sleep math for the deep dive.
How it compares
| Drink | Caffeine |
|---|---|
Oolong Tea (8oz cup) Generic | 45 mg |
| Green Tea (8oz cup) Generic | 35 mg |
| Black Tea (8oz cup) Generic | 50 mg |
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How much caffeine is in a Oolong Tea (8oz cup)?
A 8 fl oz (237 ml) Oolong Tea (8oz cup) contains approximately 45 mg of caffeine. Actual values may range from 30 to 65 mg depending on preparation and source variation.
Is Oolong Tea (8oz cup) safe during pregnancy?
The current ACOG and NHS guideline is under 200 mg of caffeine per day during pregnancy. A Oolong Tea (8oz cup) fits comfortably within that limit. Always consult your obstetrician for personalized advice.
When should I stop drinking Oolong Tea (8oz cup) for sleep?
Caffeine has a 5-hour half-life. To have under 20 mg circulating at bedtime (the typical sleep-safe threshold), stop drinking Oolong Tea (8oz cup) about 6 hours before sleep. 45 mg metabolizes cleanly. A traditional Chinese tea afternoon (3-4 cups over 2 hours) keeps you in safe territory.
Oolong Tea (8oz cup) vs Green Tea (8oz cup) — which has more caffeine?
Oolong Tea (8oz cup) contains 45 mg per serving; Green Tea (8oz cup) contains 35 mg per 8 fl oz (237 ml). Oolong Tea (8oz cup) is the stronger of the two.
Does Oolong Tea (8oz cup) keep you awake?
45 mg is mild caffeine. Most people can drink Oolong Tea (8oz cup) in the afternoon without notable sleep impact.
Caffeine values shown are typical for the listed serving size. Actual content varies by preparation, brewing method, batch, and brand reformulation. Not medical advice — consult a healthcare provider for personalized guidance.