Pyrroloquinoline quinone (PQQ) is a compound recently introduced to the supplement market, often promoted for its cellular support properties. Increased interest in this supplement necessitates a clear understanding of its safety profile and potential side effects. This article investigates the reported adverse effects, potential interactions, and established safe consumption levels of PQQ.
What is Pyrroloquinoline Quinone (PQQ)?
PQQ is a naturally occurring redox cofactor, a small molecule that assists enzymes in facilitating chemical reactions within the body. It is found in soil and various foods, including fermented soybeans, kiwi, and green peppers. PQQ’s primary function is supporting mitochondrial health, which involves generating cellular energy.
PQQ is a potent antioxidant, helping to protect cells from damage caused by harmful free radicals. It is also thought to stimulate mitochondrial biogenesis, the process of creating new mitochondria within the cells. This capacity to enhance cellular energy production and protect against oxidative stress is the main reason PQQ is used as a dietary supplement.
Reported Mild Adverse Effects
Despite its generally favorable safety profile, some individuals report experiencing non-severe reactions when beginning PQQ supplementation. Gastrointestinal reactions are frequently reported mild side effects, including nausea, stomach upset, or loose stools. This digestive discomfort is usually temporary and is more likely to occur when taking higher-than-recommended doses.
Minor neurological effects have also been noted by some users, such as mild headaches or dizziness. Because PQQ enhances cellular energy production, taking it too late in the day may lead to sleep disturbances or mild insomnia. These effects are often transient, and the body typically adjusts as supplementation continues.
Potential Interactions and Contraindicated Use
PQQ is considered safe for most healthy adults, but its use carries a higher risk in specific populations. The most significant safety concern involves interaction with certain glucose-monitoring technology. PQQ can interfere with glucose dehydrogenase PQQ (GDH-PQQ) based glucose meters used to monitor blood sugar levels.
This interference can cause falsely elevated glucose readings, posing a serious risk of inappropriate insulin dosing, especially for patients with end-stage kidney disease (ESKD) on dialysis. Caution is also warranted when combining PQQ with other medications that affect energy metabolism or mitochondrial activity. Individuals taking prescription medication should consult a healthcare provider to assess for potential interactions.
Safety data is limited regarding PQQ use in pregnant or breastfeeding individuals. The European Food Safety Authority (EFSA) excluded these groups from their safety assessment when reviewing PQQ as a novel food ingredient. Most manufacturers and health authorities advise against PQQ supplementation for pregnant and lactating women until sufficient research confirms its safety.
Establishing Safe Consumption Levels
Minimizing side effects requires adhering to appropriate dosage levels. Clinical trials in humans have generally used PQQ doses ranging from 10 milligrams (mg) to 20 mg per day. The European Food Safety Authority has identified 20 mg per day as a safe supplementation dosage for healthy adults.
Taking amounts higher than this suggested daily intake increases the chance of experiencing mild adverse effects, such as digestive upset and headaches. While PQQ is an antioxidant at standard doses, extremely excessive levels may paradoxically induce oxidative stress.
Animal studies established a No Observed Adverse Effect Level (NOAEL) of 100 mg per kilogram of body weight per day, indicating a wide margin of safety from acute toxicity. However, high doses over a prolonged period may increase the risk of kidney damage in susceptible individuals. Starting with a lower dose and taking the supplement in the morning can help the body adapt and avoid sleep disruption.