InfoSynergy
Fish Oil
Fish Oil may add modest lipid-lowering effects to Gemfibrozil for triglyceride lowering.
Recommendation: Use as part of the lipid plan, not as a substitute for prescribed therapy; recheck lipids after regimen changes.
Gemfibrozil
Prescription ·Strong evidence ·Reviewed May 2026
Gemfibrozil is a fibric acid derivative used primarily to lower very high triglyceride levels and to reduce the risk of pancreatitis in patients with severe hypertriglyceridemia. It also modestly raises HDL cholesterol and was shown in the Helsinki Heart Study and VA-HIT to reduce coronary events in selected dyslipidemic patients. It is a potent inhibitor of several drug-metabolizing and transport pathways, which gives it a high potential for clinically important drug interactions.
What it's good for
What to watch for
The bottom line
Evidence rating strong. Most-documented uses: treatment of severe hypertriglyceridemia (fredrickson types iv and v) to reduce pancreatitis risk, treatment of mixed dyslipidemia / type iib hyperlipidemia, reduction of coronary heart disease risk in selected patients with low hdl and elevated triglycerides who do not respond adequately to diet. 4 sources indexed (1987–2019), with 6 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
Gemfibrozil activates peroxisome proliferator-activated receptor alpha (PPAR-alpha), a nuclear transcription factor that regulates lipid metabolism. PPAR-alpha activation increases expression of lipoprotein lipase and reduces apolipoprotein C-III, thereby enhancing the lipolysis and clearance of triglyceride-rich very-low-density lipoproteins (VLDL). It also decreases hepatic VLDL triglyceride synthesis and secretion and increases production of apolipoproteins A-I and A-II, modestly raising HDL. Separately, gemfibrozil and its glucuronide metabolite strongly inhibit CYP2C8, the organic anion transporting polypeptide OATP1B1 (SLCO1B1), and UGT-mediated glucuronidation, which underlies its major interactions with statins and other drugs.1,2
Class
Fibrate (fibric acid derivative)
Absorption
Best on an empty stomach
Dosing
Dosing & protocol.
Common range
1200 mg per day, taken as 600 mg twice daily 30 minutes before the morning and evening meals.
Recommended form
Oral tablet (600 mg)
Well absorbed orally; bioavailability is optimized when taken about 30 minutes before meals. Administration with food can reduce bioavailability. Although gemfibrozil itself is not fat-soluble, fibrate therapy can reduce absorption of fat-soluble nutrients and, by altering bile composition, increase the risk of cholesterol gallstones; bile-acid sequestrants taken concurrently should be separated by at least 2 hours to avoid binding.3
Depletions
What it depletes.
Nutrients this medication can lower over time, and what to replace.
Coenzyme Q10
MildFibrates lower circulating cholesterol and lipoproteins, which serve as the principal transport vehicles for the lipophilic, cholesterol-pathway-derived molecule coenzyme Q10. Reduced lipoprotein carriers lower measured serum/plasma CoQ10 concentrations. Like statins, fibrates may also modestly reduce endogenous synthesis through effects on the mevalonate/isoprenoid pathway, and the proposed CoQ10 decline is one hypothesized contributor to fibrate-associated myopathy, particularly when combined with a statin.
Replace Coenzyme Q10 (ubiquinone)Monitor Plasma coenzyme Q10 level (interpret relative to total cholesterol/LDL, as CoQ10 tracks with lipoprotein concentration); creatine kinase if myopathy is suspectedOnset Weeks to a few months of continued therapy
Folate
MildFibrate therapy is associated with an increase in plasma total homocysteine, an effect attributed largely to altered renal handling/creatinine and possibly to interference with folate-dependent remethylation of homocysteine. The rise in homocysteine reflects a relative functional drain on folate (and other B vitamins) used in the methionine cycle. This effect is most robustly documented for fenofibrate and bezafibrate; data specific to gemfibrozil are more limited, so the depletion is best regarded as a possible class effect of modest magnitude.
Replace Folic acid (or L-methylfolate)Monitor Plasma total homocysteine; serum/red blood cell folateOnset Within the first weeks to months of therapy
Safety
Full safety detail.
Side effects
- Dyspepsia, abdominal pain, nausea, and diarrhea
- Cholelithiasis (gallstones) and cholecystitis due to increased biliary cholesterol excretion
- Myopathy and myalgia, with rare rhabdomyolysis especially when combined with statins
- Elevated liver transaminases
- Headache, dizziness, and fatigue
- Eczema, rash, and pruritus
- Modest decreases in hemoglobin, hematocrit, and white blood cell count early in therapy
Contraindications
- Hepatic impairment or active liver disease3
- Severe renal impairment3
- Preexisting gallbladder disease or cholelithiasis3,1
- Concomitant use with repaglinide (markedly increased plasma concentrations and hypoglycemia risk)3,4
- Concomitant use with simvastatin (markedly increased rhabdomyolysis risk)4,3
- Concomitant use with dasabuvir and selexipag3
- Known hypersensitivity to gemfibrozil1,2
Interactions
Interaction records.
InfoSynergy
Berberine
Berberine may add modest lipid-lowering effects to Gemfibrozil.
Recommendation: Use as part of the lipid plan, not as a substitute for prescribed therapy; recheck lipids after regimen changes.
ModerateCaution
Coenzyme Q10
Gemfibrozil, like statins and other fibrates, can lower circulating coenzyme Q10 (ubiquinone) concentrations and is associated with muscle-related adverse effects (myalgia, myositis, and rarely rhabdomyolysis), particularly when combined with a statin. CoQ10 is sometimes used to support mitochondrial energy production in patients with fibrate- or statin-associated muscle symptoms. While CoQ10 does not reverse the underlying myopathy risk, it is generally well tolerated and may be considered as adjunctive support; it should not be viewed as a substitute for monitoring or dose adjustment of the lipid-lowering regimen.
Recommendation: Supplementing CoQ10 (commonly 100-200 mg/day) is reasonable for patients with fibrate-associated muscle symptoms, but it does not eliminate myopathy risk. Report unexplained muscle pain, tenderness, or weakness, especially if gemfibrozil is combined with a statin, and have creatine kinase checked if symptoms occur. CoQ10 does not replace clinical monitoring.
ModerateCaution
Berberine
Berberine has lipid-lowering and glucose-lowering activity and modulates several drug-metabolizing enzymes and transporters (including CYP3A4 and CYP2D6 inhibition). Combining berberine with gemfibrozil could produce additive lipid effects of uncertain clinical value and, more importantly, may compound the metabolic-drug-interaction burden of an already potent CYP2C8/OATP1B1 inhibitor such as gemfibrozil. In diabetic or insulin-resistant patients, berberine's glucose-lowering effect may add to that of concomitant antidiabetic therapy.
Recommendation: Use berberine cautiously with gemfibrozil. Discuss with a clinician before combining, particularly if also taking statins, antidiabetic drugs, or other agents with narrow therapeutic windows. Monitor lipids, liver enzymes, and, where relevant, blood glucose. Avoid stacking multiple enzyme-inhibiting supplements with gemfibrozil.
ModerateCaution
Fish Oil
High-dose omega-3 fatty acids (EPA/DHA) and gemfibrozil are both used to lower triglycerides and are sometimes co-prescribed. Each can modestly affect platelet function and bleeding tendency, and high-dose fish oil has been associated with a small increased risk of atrial fibrillation. There is generally no harmful pharmacokinetic interaction, and the combination is sometimes intentional for severe hypertriglyceridemia, but additive antiplatelet/bleeding effects and the AF signal warrant awareness, especially alongside anticoagulants or antiplatelet drugs.
Recommendation: Co-use is often acceptable and sometimes intentional for severe hypertriglyceridemia, ideally under clinician guidance to track triglyceride response and avoid redundant therapy. Watch for easy bruising or bleeding, particularly if also taking aspirin, NSAIDs, or anticoagulants, and report new palpitations. Disclose fish oil use before any surgery.
ModerateCaution
Vitamin E
High-dose vitamin E has antiplatelet/anticoagulant properties and can potentiate bleeding risk. Gemfibrozil itself can potentiate oral anticoagulants and may modestly affect bleeding parameters. Combining high-dose vitamin E with gemfibrozil, particularly in patients also taking warfarin, other anticoagulants, or antiplatelet agents, may additively increase bleeding tendency. Routine low-dose vitamin E from diet or a standard multivitamin is unlikely to be clinically significant.
Recommendation: Keep vitamin E within ordinary dietary/multivitamin amounts; avoid high-dose vitamin E (for example, several hundred IU or more daily) with gemfibrozil unless directed by a clinician, especially if taking anticoagulant or antiplatelet medication. Watch for unusual bruising or bleeding and disclose supplement use before surgery or invasive procedures.
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
2- 1Gemfibrozil for the secondary prevention of coronary heart disease in men with low levels of high-density lipoprotein cholesterol (VA-HIT)Needs reviewPMIDRubins HB, Robins SJ, Collins D, et al. · New England Journal of Medicine · 1999
In men with coronary disease and low HDL, gemfibrozil reduced the combined risk of nonfatal myocardial infarction and coronary death by about 22% without significantly lowering LDL.
- 2Helsinki Heart Study: primary-prevention trial with gemfibrozil in middle-aged men with dyslipidemiaNeeds reviewPMIDFrick MH, Elo O, Haapa K, et al. · New England Journal of Medicine · 1987
Over 5 years gemfibrozil reduced the incidence of coronary heart disease by approximately 34% compared with placebo, driven by reductions in triglycerides and LDL and an increase in HDL.
Reference material
2- 3Lopid (gemfibrozil) US Prescribing InformationNeeds reviewNo linkParke-Davis / Pfizer · FDA prescribing information · 2019
The recommended dose is 1200 mg daily in two divided doses 30 minutes before the morning and evening meals; contraindicated with simvastatin, repaglinide, dasabuvir, and in patients with hepatic, severe renal, or gallbladder disease.
- 4Mechanisms of the gemfibrozil-statin interaction and the risk of myopathyNeeds reviewNo linkBackman JT, Kyrklund C, Neuvonen M, Neuvonen PJ · Clinical Pharmacology and Therapeutics · 2002
Gemfibrozil and its glucuronide inhibit CYP2C8, OATP1B1, and glucuronidation, raising plasma concentrations of statins such as simvastatin acid and cerivastatin and increasing myopathy and rhabdomyolysis risk.
Keep exploring
Deep dives & adjacent profiles.
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