PepsiCo
How much caffeine is in Pepsi Zero Sugar?
Data checked against the source on 2026-10-03 by Oleksii Y.
One 12 fl oz can of Pepsi Zero Sugar has 38 mg of caffeine, according to PepsiCo Product Facts.
How Pepsi Zero Sugar compares
- Strength: 11 mg per 100 ml.
- One 12 fl oz can has as much caffeine as about half a cup of brewed coffee, which has 94.8 mg per 8 fl oz cup.
- Of the 22 other sodas in our soda chart, 7 have more caffeine per serving and 14 have less.
How much will be left at bedtime?
1 × 12 fl oz can of Pepsi Zero Sugar
Left at 11:00 PM (8 h later), average metabolism
≈ 13 mg
Range 6–19 mg (fast to slow metabolism)
38 mg is already at or under the 50 mg this tool aims to have left at bedtime.
What sleep studies found near this dose
- Gardiner et al. 2025 (randomized trial): In 23 healthy young men, 100 mg taken 12, 8 or 4 hours before bed had no significant effect on measured or self-rated sleep.
- Gardiner et al. 2023 (meta-analysis): To avoid losing sleep time, the authors suggest a coffee (107 mg per 250 ml) at least 8.8 hours before bed.
Estimate from a simple model: half-life of 3, 5 or 8 hours, 50 mg bedtime target. How we calculate
How long does Pepsi Zero Sugar stay in your system?
Our model halves caffeine every 5 hours for average metabolism, and every 3 or 8 hours for fast or slow metabolism. From one 12 fl oz can of Pepsi Zero Sugar (38 mg), about 19 mg is still in your body 5 hours later and about 10 mg after 10 hours. If you clear caffeine slowly (an 8-hour half-life), about 16 mg is left after 10 hours.
Estimated caffeine left at 11:00 PM from one 12 fl oz can (38 mg), using a half-life of 5 hours for average metabolism and 3 to 8 hours for the range. How we calculate
| Had at | Left at bedtime (average) | Range |
|---|---|---|
| 8:00 AM (15 h before bed) | ≈ 5 mg | 1–10 mg |
| 12:00 PM (11 h before bed) | ≈ 8 mg | 3–15 mg |
| 3:00 PM (8 h before bed) | ≈ 13 mg | 6–19 mg |
| 6:00 PM (5 h before bed) | ≈ 19 mg | 12–25 mg |
How many fit in a day?
Reference amounts are for caffeine from all sources combined. Counted at the upper end of the stated amount, one serving at a time:
- Up to 400 mg a day for most healthy adults (FDA, EFSA): about 10 servings.
- Up to 200 mg at one time for healthy adults (EFSA): about 5 servings in one go.
- Up to 200 mg a day in pregnancy (EFSA, NHS): about 5 servings.
These are reference amounts for groups of people, not a personal limit. Some people feel jittery or sleep worse on much less. See the cutoff calculator for timing.
Good to know
Pepsi Zero Sugar lists the same 38 mg per 12 fl oz can as regular Pepsi.
Pepsi Zero Sugar vs other Pepsi drinks
- Pepsi: Pepsi Zero Sugar has the same amount of caffeine as Pepsi per 12 fl oz can: 38 mg vs 38 mg.
- Diet Pepsi: Pepsi Zero Sugar has more caffeine than Diet Pepsi per 12 fl oz can: 38 mg vs 35 mg.
Common questions
How much caffeine is in Pepsi Zero Sugar?
PepsiCo Product Facts gives 38 mg of caffeine per 12 fl oz can.
How many Pepsi Zero Sugar servings can I have in a day?
The FDA and EFSA cite up to 400 mg of caffeine a day, from all sources combined, for most healthy adults. At 38 mg per 12 fl oz can, that is about 10 servings if Pepsi Zero Sugar is your only source. In pregnancy the reference is 200 mg a day.
How late can I drink Pepsi Zero Sugar?
One serving has about 38 mg, which is at or under the 50 mg our calculator aims to have left at bedtime, so it sets no cutoff for a single serving. Several servings add up.
Does Pepsi Zero Sugar have more caffeine than Pepsi?
Pepsi Zero Sugar has the same amount of caffeine as Pepsi per 12 fl oz can: 38 mg vs 38 mg.
How long does Pepsi Zero Sugar stay in your system?
Of the 38 mg in one 12 fl oz can, roughly 19 mg remains after 5 hours and 10 mg after 10 hours with our average 5-hour half-life. From fast to slow metabolism, 10 hours later it is between 4 and 16 mg.
Where the number comes from
- Pepsi Zero Sugar - 12 fl oz. PepsiCo Product Facts. GTIN 00012000018770, nutrition facts: "Caffeine 38mg" Accessed 2026-10-02. Source ↗
- Pepsi - 12 fl oz. PepsiCo Product Facts. GTIN 00012000000133, nutrition facts: Serving Size 1 can, "Caffeine 38mg" Accessed 2026-10-02. Source ↗
Recipes and labels change. If a number here no longer matches the label, the label wins.
General information, not medical advice
If you feel unwell after caffeine — for example chest pain, a fast or irregular heartbeat that does not settle, fainting, confusion or trouble breathing — get urgent medical help. If you are pregnant or breastfeeding, under 18, take medication, or have a heart, liver or anxiety condition, high blood pressure or a sleep disorder, ask a doctor or pharmacist what amount is right for you.
Sources
- U.S. Food and Drug Administration (2024). Spilling the Beans: How Much Caffeine is Too Much? FDA Consumer Updates. fda.gov ↗
- European Food Safety Authority. Caffeine | EFSA. EFSA topic page (summary of the 2015 Scientific Opinion on the safety of caffeine). efsa.europa.eu ↗
- NHS. Foods to avoid in pregnancy. NHS. nhs.uk ↗
An app for better sleep is on the way
We’re working on a mobile app to help you sleep better. It isn’t out yet. Leave your email and we’ll let you know when it launches.