PQQ (pyrroloquinoline quinone)
Pyrroloquinoline quinone
Supplements. Modern nutrition.
Also called PQQ, Methoxatin, PQQ disodium salt
Pinyin: bǐ luò kuí lín kūn
Spanish: Pirroloquinolina quinona (PQQ)
Long-term safety unknownA helper molecule found in small amounts in some foods and bacteria, sold as a supplement for memory, energy and healthy aging.
Did you know? PQQ was first spotted in 1964 as an unknown helper molecule for an enzyme in a bacterium. Its structure was worked out in 1979 using methylotrophic bacteria, which feed on single-carbon compounds such as methanol.
What it may help, and how strong the proof is
- Memory & focus. A few small randomized trials in adults reported better memory or attention. The trials were small and short, results were mixed, and at least one was run by staff of the company that makes the ingredient. Larger, longer, independent trials are needed.See the research: 6 studies in peoplePromising proof
- Energy & tiredness. Lab and animal studies suggest PQQ supports the cell parts that make energy. Proof of more energy or stamina in people is missing.See the research: 1 study in peopleTraditional proof
Parts of the body
Traditional use
PQQ has no long history of traditional use. It came out of lab research on bacterial enzymes in the 1960s and 1970s, and supplements appeared only in recent decades.
How it is classified
- Herbal actions
- Antioxidant, Brain tonic. Energy: neutral.
How people take it
Human trials used about 20 mg a day for 12 weeks, which is also the daily cap in the European Food Safety Authority's 2017 safety opinion. Talk with a doctor before starting, especially if you take daily medicines.
Capsule and powder.
Where to get it
PQQ is found in small amounts in some foods, such as kiwi, green peppers, parsley, papaya, tofu and natto. Most people who use it take a supplement, sold as capsules or powder in stores and online. Many products use the disodium salt form.
Be careful
The European Food Safety Authority judged PQQ disodium salt safe for healthy adults at up to 20 mg a day in 2017, but its opinion excluded pregnant and lactating women, and long-term human data are limited. Avoid it in pregnancy and breastfeeding, and ask a doctor first if you take daily medicines, since drug mixes are not well studied. Safety in children has not been studied.
Avoid if: pregnancy; breastfeeding; children under 12.
Mixing with other things
- Works well together
Both are sold as energy support for cells. Few studies have tested them together.
- Works well together
Both are sold for cell energy and healthy aging. Neither has strong human proof yet.
The honest take
PQQ plays a real role as a helper for certain enzymes. In people, a few small trials suggest possible memory or attention gains, but results were mixed, and at least one was run by the company that makes the ingredient. Its status as a vitamin is not settled, and long-term safety is not known.
Sources
Each “See the research” link opens PubMed, the U.S. National Library of Medicine's index of medical studies, showing only trials and reviews done in people. The number tells you how much a use has been tested, not whether it worked. The proof rating tells you that.
Study counts checked October 2026.