C4
People mainly take C4 for energy, performance, focus. Based on 14 first-hand reports. Ranked #1182 of 3,539 overall.
Of reports that state an outcome, 30% are positive.
What C4 does, according to users
Of the people who reported each effect, the share who said it got better.
3 more with fewer than 3 reports
What the research says
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
Dosage people report
As stated by users — not a recommendation. Follow the label or your doctor.
Reported side effects
How often each side effect came up across all reports.
What users say
First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.
“I was doing 2 scoops of C4 and a 30mg XR and had some amazing workouts.”
“I had a terribly tough time falling asleep. A couple times I couldn't sleep at all. I may be stimulant sensitive.”
“I started off with one scoop and ended up with 5 scoops and 5 scoops didn't do anything”
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 3, 2026. How we rate