# Menthol

> Menthol is an isolated compound rather than a whole plant drug. Oral (lozenges): 5-10 mg per lozenge. Inhalation: 2-5 drops in steam. Internal: 0.2-0.4 mL Peppermint|peppermint oil (50-55% menthol) in enteric-coated capsules.

## Names and identification

| Language | Name |
|----------|------|
| English | Menthol |

## What is it made of?

### Key Active Markers

- Derived from constituent herbs (see individual herb profiles)
- Standardized on primary bioactive markers

**Analytical Methods:** HPLC fingerprinting, TLC (identity), LC-MS/MS (marker quantification)

## Dosage forms and preparation

**Dosage Forms:** Crystals (topical), Essential oil, Inhalation preparation, Lozenges, Topical balm/ointment, Gel, Nasal spray, Oral thin films, Transdermal patches

**Standard Dosage:** Topical: 1-10% in formulations. Oral (lozenges): 5-10 mg per lozenge. Inhalation: 2-5 drops in steam. Internal: 0.2-0.4 mL peppermint oil (50-55% menthol) in enteric-coated capsules.

**Bioavailability:** Excellent bioavailability via all routes. Oral: approximately 40-50% bioavailable with significant first-pass hepatic glucuronidation. Topical: rapidly penetrates skin reaching dermal tissue within 5-10 minutes. Inhalation: near-instant mucosal absorption with rapid onset of action. TRPM8 receptor activation occurs at sub-micromolar concentrations making menthol highly potent topically.

**Optimal Timing:** Topical: as needed for pain or cooling. Lozenges: as needed for throat/nasal congestion. Enteric capsules: 30 minutes before meals for IBS. Inhalation: as needed for respiratory relief.

**Standardized Extract:** Natural L-Menthol crystals (minimum 99.0% purity, BP/USP grade). Dementholized peppermint oil (menthol removed, remaining terpenes). Menthol-in-cyclodextrin complex for controlled release. Microencapsulated menthol for extended topical effect.

**Shelf Life:** Menthol crystals: 60 months in sealed containers. Topical products: 24-36 months. Lozenges: 24 months. Essential oil: 36 months sealed.

**Storage:** Store menthol crystals in airtight glass containers at 15-25 deg C (sublimes at higher temperatures). Protect from heat and light. Essential oil in amber glass, tightly sealed. Topical products at room temperature. Lozenges in individually wrapped, moisture-proof packaging.

**Marker Compounds:** L-Menthol, [Menthone](/glossary/compounds-l-o/#menthone), Menthyl acetate, [Isomenthone](/glossary/compounds-g-l/#isomenthone), Neomenthol, [Pulegone](/glossary/compounds-o-q/#pulegone) (impurity, must be below 1%)

### Extraction Methods

- Fractional distillation of peppermint oil (Mentha piperita/M. arvensis)
- Crystallization from cornmint oil at -22 deg C
- Synthetic production from [thymol](/glossary/compounds-t-z/#thymol) or [citronellal](/glossary/compounds-c-d/#citronellal)
- Semi-synthetic from natural d-[limonene](/glossary/compounds-g-l/#limonene)
- Freeze crystallization for pharmaceutical-grade crystals

### Synergistic Combinations

- [Camphor](/herb/camphor/) (counter-irritant [analgesic](/reference/analgesic/) combination)
- Methyl salicylate (pain relief synergy in balms)
- [Eucalyptus](/herb/eucalyptus/) oil (respiratory decongestant)
- Capsaicin (hot-cold analgesic therapy)
- Mentha piperita oil (complete peppermint spectrum)

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Canonical version of this page: https://nighantu.ageayurveda.com/herb/menthol/

## Sources

- Amidha Ayurveda Herb Database (700+ herbs, CC-BY-4.0)
- AgeAyurveda Product Catalog
- Ayurvedic Pharmacopoeia of India

Published by Age Ayurveda in the Nighantu. Educational reference only, not medical advice.
Incorporates material from the Amidha Ayurveda Herb Database under CC BY 4.0.