Inositol Hexanicotinate (IHN)

Evidence Level
Limited
2 Clinical Trials
4 Documented Benefits
2/5 Evidence Score

Inositol hexanicotinate (IHN), also known as inositol hexaniacinate or sold as 'no-flush niacin', is a compound consisting of six niacin molecules ester-linked to a single inositol molecule. It was developed in mid-20th-century Europe (where it is marketed as Hexopal) and was hoped to offer the cardiovascular and lipid effects of immediate-release niacin without the characteristic skin-flushing reaction. However, the bioavailability and clinical effects of IHN have proved controversial. Multiple pharmacokinetic studies have shown that IHN releases very little free nicotinic acid into circulation in humans, and head-to-head clinical trials have found that IHN does NOT meaningfully alter lipid parameters in the way that prescription immediate- or extended-release niacin does. Honest discussion of IHN therefore requires acknowledging that, despite widespread marketing, its evidence for lipid support is largely negative.

Studied Dose Trials and marketed products typically deliver 500-2,000 mg/day in divided doses; clinical effects on lipids at these doses have been minimal compared with pharmaceutical niacin.
Active Compound Inositol hexanicotinate (six nicotinic acid molecules ester-linked to myo-inositol).

Benefits

Niacin-Form Marketed as Flush-Free

IHN is positioned as a niacin-providing supplement that avoids the warm flushing reaction associated with immediate-release nicotinic acid. Users sensitive to flushing may prefer this form, though its biological activity differs substantially from that of free niacin.

Traditional Use in Vascular Comfort

European clinicians have historically used IHN under the name Hexopal for conditions involving peripheral circulation, with small early trials suggesting subjective improvements in cold-hand symptoms in Raynaud's phenomenon.

Source of Inositol and Niacin Building Blocks

Although release of free nicotinic acid is limited, IHN does provide the molecular components of inositol and niacin to the body, contributing in small amounts to overall intake of these nutrients.

Reported Mild Tolerability

Trial data indicate IHN is generally well tolerated at typical supplement doses, with side effects comparable to placebo in published studies — though this favorable tolerability profile also reflects its limited pharmacologic activity.

Mechanism of action

1

Slow Ester Hydrolysis (Proposed)

IHN was designed on the assumption that intestinal and tissue esterases would slowly hydrolyze the ester bonds to release nicotinic acid gradually. In practice, human pharmacokinetic data show this release is minimal at typical supplement doses.

2

Minimal Nicotinic Acid Bioavailability

Clinical pharmacokinetic studies in humans have demonstrated that oral IHN produces very low plasma concentrations of free nicotinic acid compared with immediate- or extended-release niacin, explaining the lack of robust lipid effects.

3

Niacinamide Conversion

A portion of any niacin released from IHN is rapidly converted to niacinamide, which does not engage the GPR109A receptor responsible for niacin's lipid-modulating effects.

Clinical trials

1
IHN vs. Wax-Matrix Niacin for Lipids

Randomized comparison of wax-matrix extended-release niacin and IHN in adults with metabolic syndrome

Adults with metabolic syndrome and dyslipidemia

Wax-matrix extended-release niacin produced expected lipid changes, whereas inositol hexanicotinate failed to meaningfully alter lipid parameters compared with baseline. The trial concluded that IHN should not be considered equivalent to pharmaceutical niacin for lipid management.

2
Hexopal in Primary Raynaud's Disease

Double-blind, randomized, placebo-controlled trial of inositol hexanicotinate

Patients with primary Raynaud's phenomenon

The trial reported some symptomatic improvement with IHN compared with placebo in Raynaud's symptoms, although follow-up evidence has been limited and the magnitude of effect modest, leaving the role of IHN uncertain even for peripheral vascular comfort.

Side effects and drug interactions

Common Potential side effects

Generally well tolerated with side effects comparable to placebo in trials.
Mild gastrointestinal upset such as nausea may occur occasionally.
Unlike free niacin, flushing is rare due to limited nicotinic acid release.
Headache reported infrequently at higher doses.
Marketed claims of equivalence to prescription niacin are not supported by current trial evidence.

Important Drug interactions

Theoretical interactions with lipid-modifying medications, though clinically minor due to low bioavailability.
Use caution with anticoagulants such as warfarin given niacin-related effects on platelets.
May modestly interact with antihypertensive medications.
Discuss with a clinician before using as a replacement for prescription niacin therapy.

Frequently asked questions about Inositol Hexanicotinate (IHN)

What is the recommended dosage of Inositol Hexanicotinate (IHN)?

The clinically studied dose for Inositol Hexanicotinate (IHN) is Trials and marketed products typically deliver 500-2,000 mg/day in divided doses; clinical effects on lipids at these doses have been minimal compared with pharmaceutical niacin.. Always follow product labeling and consult a healthcare provider for personalized dosing recommendations.

What is Inositol Hexanicotinate (IHN) used for?

Inositol Hexanicotinate (IHN) is studied for niacin-form marketed as flush-free, traditional use in vascular comfort, source of inositol and niacin building blocks. IHN is positioned as a niacin-providing supplement that avoids the warm flushing reaction associated with immediate-release nicotinic acid.

Are there side effects from taking Inositol Hexanicotinate (IHN)?

Reported potential side effects may include: Generally well tolerated with side effects comparable to placebo in trials. Mild gastrointestinal upset such as nausea may occur occasionally. Always consult a healthcare provider before starting any new supplement, especially if you have underlying conditions or take medications.

Does Inositol Hexanicotinate (IHN) interact with medications?

Known drug interactions may include: Theoretical interactions with lipid-modifying medications, though clinically minor due to low bioavailability. Use caution with anticoagulants such as warfarin given niacin-related effects on platelets. Consult a pharmacist or healthcare provider if you take prescription medications.

Is Inositol Hexanicotinate (IHN) good for cardiovascular?

Yes, Inositol Hexanicotinate (IHN) is researched for Cardiovascular support. IHN is positioned as a niacin-providing supplement that avoids the warm flushing reaction associated with immediate-release nicotinic acid. Users sensitive to flushing may prefer this form, though its biological activity differs substantially from that of free niacin.

References(2 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Keenan JM. Wax-matrix extended-release niacin vs inositol hexanicotinate: a comparison of wax-matrix, extended-release niacin to inositol hexanicotinate 'no-flush' niacin in persons with mild to moderate dyslipidemia. Journal of Clinical Lipidology. 2013;J Clin Lipidol. 2013 Jan-Feb;7(1):14-23..PubMedUsed to support: Head-to-head trial demonstrating that inositol hexanicotinate ('no-flush niacin') failed to meaningfully change lipid parameters, while wax-matrix extended-release niacin produced the expected lipid-modifying effects. Concludes IHN is not pharmacologically equivalent to niacin for lipid management.
  2. Sunderland GT, Belch JJ, Sturrock RD, Forbes CD, McKay AJ. A double blind randomised placebo controlled trial of hexopal in primary Raynaud's disease. Clinical Rheumatology. 1988;Clin Rheumatol. 1988 Mar;7(1):46-9..PubMedUsed to support: Early double-blind, placebo-controlled trial of inositol hexanicotinate (Hexopal) in primary Raynaud's disease reporting modest symptomatic effects; subsequent work has not established robust lipid or vascular benefits, and overall evidence for IHN remains weak.