What it is
Regulatory status: OTC dietary supplement in the US, EU and most markets
At a glance
What it is, why people use it, the evidence, and what to know before trying it.
Why people use it
- Heart-failure symptoms, hospitalisation, and death (the Q-SYMBIO claim).
- Relief of statin-associated muscle symptoms (pain, cramp, weakness) and better statin adherence.
- Migraine prophylaxis: fewer attacks, shorter attacks, less severe attacks.
- Male fertility: better semen parameters and more pregnancies.
- Athletic / exercise performance (VO2max, time to exhaustion, power, less fatigue).
- Higher plasma CoQ10 (sold as if it were the clinical outcome).
- CoQ10 100 mg + PQQ 10 mg as a mitochondrial “stack” (claim only; PQQ not reviewed).
Evidence at a glance
CoQ10 is a real mitochondrial cofactor and a real plasma-raising supplement. That is not the same as a real treatment. The only hard-outcome signal is **Q-SYMBIO**: ubiquinone **300 mg/day** for 2 years cut MACE (HR 0.50) and all-cause death (10% vs 18%) in 420 moderate-severe HF patients, and Cochrane 2021 grades that mortality/hospitalisation effect moderate-quality — but the mortality meta **is Q-SYMBIO**, the trial missed its short-term endpoints, stopped early at 420/550 after eight years of enrolment, was Association- and Kaneka-supported, and has **not been independently replicated** on 2020s GDMT. ACC/AHA/ESC do not recommend it. **SAMS** has conflicting small-trial metas and a null confirmed-myalgia RCT at **600 mg ubiquinol**; muscle CoQ10 does not reliably rise. **Migraine** has a real but small monotherapy signal (Sándor n = 42, ~1.5 fewer attacks/month in meta, AHS/AAN Level C). **Fertility** improves semen numbers; **live birth is not shown**. **Exercise performance** does not follow the plasma rise. **50–100 mg, 60 mg BID, 50 mg ubiquinol-in-a-multi, and 100 mg+PQQ 10 mg** are not the evidence-bearing doses.