Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FENOFIBRIC ACID vs NIACOR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Fenofibric acid is a peroxisome proliferator-activated receptor alpha (PPARα) agonist that increases lipolysis and clearance of triglyceride-rich lipoproteins and reduces apolipoprotein C-III production, leading to decreased triglycerides and increased HDL cholesterol.
Niacin (nicotinic acid) reduces VLDL and LDL synthesis by inhibiting lipolysis in adipose tissue, decreasing free fatty acid flux to the liver, and inhibiting hepatic triglyceride synthesis. It also increases HDL by reducing catabolism of apolipoprotein A-I.
Adjunct to diet for treatment of severe hypertriglyceridemia (Fredrickson types IV and V hyperlipidemia),Adjunct to diet for reduction of LDL-C, total-C, triglycerides, and Apo B in primary hypercholesterolemia or mixed dyslipidemia (Fredrickson types IIa and IIb)
Adjunct to diet for reduction of elevated total cholesterol, LDL-C, apo B, and triglyceride levels, and to increase HDL-C in primary hypercholesterolemia and mixed dyslipidemia,Adjunct to diet for reduction of risk of recurrent myocardial infarction in patients with coronary artery disease and hypercholesterolemia,Adjunct to diet for slowing progression of coronary atherosclerosis,Off-label: treatment of pellagra (niacin deficiency)
135 mg orally once daily
Initial: 250 mg orally once daily after evening meal; titrate up by 250–500 mg/day every 2–4 weeks. Maintenance: 1–2 g/day in divided doses (2–3 times daily). Maximum: 6 g/day.
Terminal elimination half-life is approximately 20 hours (range 15-25 h) for fenofibric acid, supporting once-daily dosing. In renal impairment, half-life may be prolonged.
20–45 minutes for immediate-release niacin; terminal half-life of main metabolites (nicotinuric acid) is approximately 1.5–4 hours; short half-life necessitates multiple daily dosing for lipid effects
Primarily hepatic via glucuronidation; minor CYP3A4 involvement. Excreted as glucuronide conjugates in urine and feces.
Hepatic metabolism via two pathways: conjugation with glycine to form nicotinuric acid (major, low-affinity high-capacity) and oxidation to N-methylnicotinamide and other metabolites (minor, high-affinity low-capacity). Enzymes involved: nicotinamide N-methyltransferase (NNMT) and aldehyde oxidase.
Primarily renal as unchanged drug and glucuronide conjugate (approximately 60-70% of dose); remainder eliminated via biliary/fecal routes (~25%).
Renal: 60-88% as unchanged drug and metabolites after oral administration; fecal: <2%
Highly bound to serum albumin (approximately 99%).
<20% bound to albumin; minimal binding to other plasma proteins
Approximately 0.4 L/kg (range 0.2-0.6 L/kg), indicating distribution mainly in extracellular fluid.
0.5–0.7 L/kg; indicates distribution into total body water and some tissue binding
Oral bioavailability of fenofibric acid is approximately 100% when administered as the choline salt; the capsule formulation has high bioavailability relative to tablet. Food may reduce rate but not extent of absorption.
Oral immediate-release: 60–76% (variable due to first-pass metabolism); sustained-release: lower bioavailability (50–60%) due to increased presystemic metabolism
If e GFR 30-59 m L/min: reduce dose to 45 mg orally once daily. If e GFR <30 m L/min: contraindicated.
No specific adjustment recommended; use caution in severe renal impairment (Cr Cl <30 m L/min) due to potential accumulation; consider reducing dose or prolonging interval.
Contraindicated in Child-Pugh class B or C; no dose adjustment defined for Child-Pugh A (use with caution).
Contraindicated in Child-Pugh class B and C; use with caution in mild impairment (Child-Pugh A) with dose reduction of 50% initially.
Not approved for use in pediatric patients.
For hyperlipidemia (off-label): Initial 50–100 mg/kg/day orally divided into 2–3 doses; titrate over 4–6 weeks up to 200–300 mg/kg/day; maximum 6 g/day. Not recommended in children <2 years.
No specific dose adjustment required; consider renal function and potential for decreased renal clearance in elderly.
Start at lowest dose (250 mg daily); titrate slowly due to increased risk of flushing, hypotension, and hepatotoxicity; monitor liver function and glucose closely.
None
None.
Hepatotoxicity: elevation of serum transaminases; contraindicated in active liver disease.,Myopathy/rhabdomyolysis risk, especially with statins or in patients with renal impairment, hypothyroidism, or alcohol abuse.,Cholelithiasis: risk of gallstones due to increased cholesterol excretion into bile.,Pancreatitis: reported in hypertriglyceridemia patients.,Renal impairment: dose adjustment required; avoid in severe renal disease.,Venothromboembolic events: increased risk in clinical trials.
Hepatotoxicity: elevated liver enzymes, hepatitis; discontinue if persistent elevations occur,Flushing: prostaglandin-mediated, can be reduced by taking aspirin prior; tolerance develops,Hyperuricemia: may precipitate gout,Hyperglycemia: may increase blood glucose; use with caution in diabetes,Peptic ulcer disease: reactivation may occur,Hypotension: can occur, especially with vasoactive drugs
Active liver disease including primary biliary cirrhosis and unexplained persistent liver function abnormalities.,Known gallbladder disease (cholelithiasis).,Severe renal impairment (e GFR <30 m L/min/1.73 m²).,Hypersensitivity to fenofibrate or fenofibric acid.
Hypersensitivity to niacin or any component of formulation,Significant or unexplained hepatic dysfunction,Active peptic ulcer disease,Arterial hemorrhage
Take with food to enhance absorption and reduce gastrointestinal intolerance. Avoid high-fat meals as they may exacerbate hypertriglyceridemia and reduce drug efficacy.
Avoid high-fat meals as they may increase risk of flushing. Take with low-fat snack. Alcohol and hot drinks can exacerbate flushing.
Pregnancy Category C. First trimester: Data insufficient to assess risk; animal studies show embryotoxicity and teratogenicity at high doses. Second/third trimesters: Avoid use due to potential fetal harm; no well-controlled human studies.
FDA Pregnancy Category C. Niacin is not recommended for use in pregnant women due to potential fetal harm, though no well-controlled studies exist. In animal studies, high doses have caused fetal abnormalities. First trimester: Avoid use due to theoretical risk of teratogenicity. Second and third trimesters: Use only if clearly needed, as niacin can cause vasodilation and potential hypotension, which may reduce uteroplacental perfusion.
Excreted in breast milk in rats; human data unknown. Use caution, especially in preterm or jaundiced infants. M/P ratio not established.
Niacin is excreted into human breast milk in minimal amounts; M/P ratio unknown. The American Academy of Pediatrics considers niacin compatible with breastfeeding. However, high maternal doses may lead to adverse effects in the infant due to potential accumulation. Caution is advised; monitor infant for flushing or gastrointestinal disturbances.
Avoid use during pregnancy; no established safe dose. Pharmacokinetic changes (increased volume of distribution, clearance) may reduce efficacy; dose adjustments not recommended due to potential fetal risk.
No specific dose adjustments recommended due to lack of pharmacokinetic studies in pregnant women. However, physiological changes in pregnancy (increased plasma volume, renal clearance) may reduce niacin levels, potentially requiring dose increase. Use the lowest effective dose and avoid extended-release formulations due to higher hepatotoxicity risk. Usual adult doses (500-2000 mg/day) may be used with caution.
Fenofibric acid is a PPARα agonist that reduces triglycerides by 30-50% and increases HDL; monitor renal function as dose adjustment required for Cr Cl 30-59 m L/min; contraindicated in severe renal impairment (Cr Cl <30 m L/min) and active liver disease; may increase serum creatinine; use with caution in patients with gallbladder disease; can potentiate warfarin effect (monitor INR).
Niacor (niacin) can cause profound flushing, which may be mitigated by taking aspirin 30 minutes prior or using extended-release formulations. Monitor liver function and blood glucose, as niacin can elevate transaminases and worsen glycemic control. Patients with gout may experience increased uric acid levels.
Take with food to reduce GI side effects.,Report unexplained muscle pain, tenderness, or weakness, especially if accompanied by fever or malaise.,Avoid alcohol as it can increase triglyceride levels and worsen liver effects.,This medication is not a substitute for diet and exercise; continue lifestyle modifications.,Notify your doctor if you develop abdominal pain (possible gallstones).
Take with food to reduce stomach upset.,Do not crush or chew extended-release tablets.,Flushing is common and may decrease with continued use.,Avoid alcohol and hot beverages near dosing time to reduce flushing.,Report unexplained muscle pain, tenderness, or weakness.,Monitor blood sugar if diabetic.,Do not substitute with dietary supplements without doctor approval.
"Fenofibric acid, a peroxisome proliferator-activated receptor alpha (PPARα) agonist, may reduce the therapeutic efficacy of ursodeoxycholic acid (UDCA) by increasing the biliary excretion of cholesterol and altering bile acid composition, thereby counteracting the beneficial effects of UDCA in dissolving cholesterol gallstones and improving cholestatic liver diseases. This interaction can lead to reduced clinical response, including incomplete stone dissolution or worsening of liver function tests in conditions such as primary biliary cholangitis."
"Glisoxepide may increase the hypoglycemic activities of Fenofibric acid."
"Colchicine may increase the myopathic rhabdomyolysis activities of Fenofibric acid."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about FENOFIBRIC ACID vs NIACOR, answered by our medical review team.
FENOFIBRIC ACID is a Antilipemic that works by Fenofibric acid is a peroxisome proliferator-activated receptor alpha (PPARα) agonist that increases lipolysis and clearance of triglyceride-rich lipoproteins and reduces apolipoprotein C-III production, leading to decreased triglycerides and increased HDL cholesterol.. NIACOR is a Antilipemic agent that works by Niacin (nicotinic acid) reduces VLDL and LDL synthesis by inhibiting lipolysis in adipose tissue, decreasing free fatty acid flux to the liver, and inhibiting hepatic triglyceride synthesis. It also increases HDL by reducing catabolism of apolipoprotein A-I.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between FENOFIBRIC ACID and NIACOR depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of FENOFIBRIC ACID is: 135 mg orally once daily. The standard adult dose of NIACOR is: Initial: 250 mg orally once daily after evening meal; titrate up by 250–500 mg/day every 2–4 weeks. Maintenance: 1–2 g/day in divided doses (2–3 times daily). Maximum: 6 g/day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between FENOFIBRIC ACID and NIACOR in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. FENOFIBRIC ACID is classified as Category C. Pregnancy Category C. First trimester: Data insufficient to assess risk; animal studies show embryotoxicity and teratogenicity at high doses. Second/third trimesters: Avoid use due. NIACOR is classified as Category C. FDA Pregnancy Category C. Niacin is not recommended for use in pregnant women due to potential fetal harm, though no well-controlled studies exist. In animal studies, high doses ha. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.