Liquiritin is a flavonoid glycoside found in licorice roots (mainly Glycyrrhiza uralensis and Glycyrrhiza glabra). Unlike glycyrrhizin—the compound in licorice most associated with blood-pressure and potassium issues—liquiritin is a polyphenol known for antioxidant, anti-inflammatory, and skin-calming activity in preclinical studies. Interest in liquiritin has grown for two practical reasons: topical use for uneven skin tone (particularly melasma) and oral use in botanical blends aiming to support mood, oxidative balance, and microcirculation. Evidence in humans is still limited, but topical trials and a rapidly expanding lab literature make liquiritin a compelling candidate for targeted, cautious use. In this guide, you’ll learn what liquiritin is (and is not), the benefits that are better supported, how to use it without overpromising, the difference between topical and oral dosing, quality checks when buying products, and the safety details that matter—especially for people with cardiovascular, renal, or endocrine concerns.
Fast Facts
- Topical liquiritin (1–4%) has clinical signals for melasma and tone evenness when used twice daily with photoprotection.
- Oral liquiritin appears antioxidant and anti-inflammatory in animal and cell models; human outcome data are preliminary.
- Practical ranges: topical 1–4% twice daily; oral products commonly supply 20–200 mg/day liquiritin from standardized extracts.
- Avoid unsupervised use if pregnant, breastfeeding, or if you have hypertension, kidney disease, or take drugs affected by licorice constituents.
Table of Contents
- What is liquiritin?
- Does it work and key uses
- How to use liquiritin
- What affects results
- Mistakes and troubleshooting
- Safety and who should avoid
- Evidence snapshot and research gaps
What is liquiritin?
A specific molecule from licorice, not “licorice” itself.
Liquiritin is a flavonoid glycoside composed of the aglycone liquiritigenin linked to a sugar moiety. It occurs naturally in licorice roots alongside related compounds (isoliquiritin, liquiritigenin, licochalcones, glycyrrhizin, and others). Each has different pharmacology. Most safety headlines about licorice—water retention, hypertension, and low potassium—come from glycyrrhizin and its metabolite glycyrrhetinic acid, which can inhibit 11β-HSD2 and mimic cortisol. Liquiritin does not share that mechanism. However, many over-the-counter products labeled “licorice extract” contain mixtures; unless a product is standardized and tested, you cannot assume it is glycyrrhizin-free.
How it works (mechanistic overview).
- Antioxidant and cytoprotective: Scavenges reactive oxygen species and upregulates endogenous defenses in preclinical models (e.g., boosting G6PD expression in neurons).
- Anti-inflammatory: Modulates NF-κB and NLRP3 inflammasome signaling in cell and animal studies; lowers pro-inflammatory cytokines (IL-1β, IL-6, TNF-α).
- Pigmentation pathways: In skin models, liquiritin may reduce melanin accumulation primarily by dispersing melanin and calming local inflammation rather than by strongly inhibiting tyrosinase (the enzyme targeted by hydroquinone).
- Neurobehavioral signals: Rodent studies show antidepressant-like effects in chronic stress paradigms, with changes in neuroinflammation and HPA-axis markers. These are hypothesis-generating, not clinical proof.
Forms you’ll encounter.
- Topicals: Creams, gels, or serums standardized to 1–4% liquiritin, often paired with sunscreen during the day and a retinoid or niacinamide at night.
- Oral supplements: Capsules or powders listing “licorice extract standardized to X% liquiritin” or “liquiritin (purified)” as the active. Typical serving sizes claim 20–200 mg liquiritin per day, sometimes in combination with other flavonoids (e.g., licochalcone A/B) or with vitamin C.
- Herbal formulas: Traditional combinations (decoctions, granules) where liquiritin is one of many constituents; the actual daily liquiritin yield varies widely.
What it is not.
A cure-all for skin or mood. For pigmentation concerns, liquiritin is adjunctive to sun protection; for mood, it is not a substitute for evaluation, therapy, sleep, and exercise. Think of liquiritin as a targeted lever with modest expected effects when the broader routine is sound.
Does it work and key uses
Skin tone and melasma (topical).
Human dermatology studies have examined liquiritin creams in melasma. In a controlled, split-face trial, topical liquiritin applied twice daily for several weeks improved hyperpigmentation compared with vehicle. Additional comparative work suggests 2–4% liquiritin can soften epidermal melasma with good tolerability. Effects are generally gradual and modest to moderate, best seen when paired with daily, broad-spectrum photoprotection and realistic expectations. Liquiritin appears less irritating than hydroquinone and may suit those with sensitive skin, though it is not necessarily stronger.
Calming irritated or redness-prone skin (topical).
By modulating inflammatory signals and oxidative stress, liquiritin-containing topicals can support barrier comfort. In practice, users report smoother tone and less reactivity when formulas are well designed (non-fragrant, pH-appropriate) and the rest of the routine (cleanser, moisturizer, sunscreen) is stable.
Oral antioxidant and neurobehavioral support (emerging).
Animal models show that oral liquiritin can reduce neuroinflammation, improve markers tied to stress resilience, and protect neural and microvascular tissues under oxidative load. Early mechanistic and pharmacokinetic work indicates reasonable oral absorption of the glycoside, with gut metabolism contributing to the systemic profile. Translating those signals to humans requires well-controlled trials. For now, any oral claims should be framed as supportive rather than therapeutic.
Respiratory and cardiometabolic angles (preclinical).
Experimental studies describe anti-inflammatory effects in airway models and protection in ischemia-reperfusion injury or endothelial stress. While intriguing, these are not clinical indications.
Where expectations should be cautious.
- Mood and cognition: Rodent data are promising; human RCTs are lacking. Consider liquiritin only as a complement to proven strategies.
- Weight, acne, or “detox”: Evidence is insufficient for meaningful, direct effects. Any improvements typically reflect routines (sleep, diet, sunscreen, skincare adherence) rather than liquiritin alone.
Bottom line.
Best-supported use today is topical liquiritin for melasma and tone uniformity with sunscreen. Oral use remains exploratory—reasonable as part of a balanced plan when products are standardized and safety boxes are ticked.
How to use liquiritin
Topical use (most practical evidence).
- Concentration: 1–4% liquiritin in a cosmetically elegant base.
- Routine: Apply twice daily to clean, dry skin on areas of uneven tone. In the morning, follow with broad-spectrum SPF 30–50. At night, moisturize; optionally layer with niacinamide or a retinoid (if your skin tolerates it).
- Timeline: Expect early changes around 4–6 weeks, with clearer gains by 8–12 weeks. Maintain sunscreen to prevent rebound.
- Pairings: Liquiritin plays well with azelaic acid, niacinamide, vitamin C derivatives, and non-fragrant moisturizers. Introduce actives one at a time to avoid irritation.
Oral use (cautious, due to limited human data).
- What labels show: Standardized licorice extracts declaring X% liquiritin or purified liquiritin (less common). Daily servings typically yield 20–200 mg liquiritin.
- Starting point: If you and your clinician agree to a trial, start at the low end (20–50 mg/day liquiritin) for 2–4 weeks, taken with food.
- Escalation: If well tolerated and you have a clear, trackable goal (e.g., skin support alongside topical care, perceived stress support), consider up to 100–200 mg/day from a tested product.
- Cycles: Use 8–12 week cycles with breaks, reassessing benefits and any side effects.
- Stacking: Combine with sleep, exercise, and nutrition fundamentals first. For skin goals, emphasize topical routine over higher oral doses.
Buying guide (quality signals).
- Standardization: The label should state liquiritin content per serving (mg) and the extraction ratio or solvent.
- Glycyrrhizin control: Prefer products that are glycyrrhizin-reduced or quantified, with third-party testing (COA) for glycyrrhizin and heavy metals.
- Transparency: Lot-specific COAs covering identity, potency, microbial limits, residual solvents, and pesticides.
- Formulation: Minimal excipients; avoid proprietary blends that obscure actual liquiritin mg.
Tracking results.
- Skin: Use standardized photos (same lighting/angle), a simple hyperpigmentation score (0–10), and note sunscreen adherence.
- Well-being: Track sleep hours, perceived stress (0–10), and exercise recovery weekly. Decide based on data, not hope.
What affects results
Delivery and bioavailability.
Liquiritin is a glycoside; gut enzymes and microbiota can split off the sugar to yield liquiritigenin, which may have distinct activity. The extract matrix, co-ingested food, and microbiome composition influence how much of each form reaches circulation. For topicals, vehicle technology (emulsifiers, penetration enhancers, pH) and concentration drive outcomes more than brand name.
Dose and timing.
For the skin, consistent twice-daily topical use beats sporadic application. For oral use, split dosing with meals can improve tolerance and maintain steadier exposure. Avoid large, untested doses—more is not necessarily better and increases the chance of side effects.
Sun exposure and skincare basics.
UV and visible light drive melanogenesis. Even the best pigment-evening agent will disappoint without daily sunscreen and shade practices. Additionally, a gentle cleanser, barrier-supporting moisturizer, and avoidance of irritants determine whether a brightening routine succeeds.
Synergy and complements.
- Niacinamide (2–5%) can reduce transfer of melanosomes and calm redness, complementing liquiritin’s soothing profile.
- Azelaic acid (10–15%) offers anti-inflammatory and melanogenesis-modulating effects without hydroquinone-like risks.
- Vitamin C derivatives support antioxidant tone; select stable formats to minimize irritation.
- Retinoids accelerate cell turnover; introduce slowly to avoid barrier disruption.
Lifestyle context.
Sleep debt, high-glycemic diet, and smoking heighten oxidative and inflammatory tone. Liquiritin will not offset those drivers. A diet rich in colored plants (berries, leafy greens), adequate protein, and steady hydration amplifies any supplement or topical plan.
Genetic and hormonal factors.
Melasma often flares with hormonal changes and photosensitizing medications. Liquiritin can help even tone but won’t correct the underlying triggers. Discuss persistent or recurrent pigmentation with a dermatologist for comprehensive care.
Mistakes and troubleshooting
Mistake 1: Treating “licorice” and “liquiritin” as synonyms.
Many licorice products are not standardized for liquiritin and may contain significant glycyrrhizin, raising the risk of hypertension and hypokalemia when overused.
Fix: Choose standardized liquiritin with glycyrrhizin content disclosed (or minimized) and verified by third-party testing.
Mistake 2: Skipping sunscreen while chasing brightening.
Sunlight will undo gains.
Fix: Daily broad-spectrum SPF 30–50, reapplied with outdoor exposure, is non-negotiable.
Mistake 3: Megadosing oral extracts.
Large doses add cost and potential risk without clear human data to justify them.
Fix: Start low (e.g., 20–50 mg/day liquiritin), track objective markers, and cap totals near 100–200 mg/day unless a clinician advises otherwise.
Mistake 4: Layering too many actives at once.
Irritation worsens pigmentation.
Fix: Introduce one active every 2–3 weeks, keeping a simple base routine.
Mistake 5: Expecting quick results.
Topical improvements are gradual.
Fix: Reassess at 8–12 weeks, not 8–12 days. Keep photos and adherence logs.
Troubleshooting quick list
- Stinging with a serum: Switch to a cream base, reduce frequency, or buffer with moisturizer.
- Patchy response: Check sunscreen coverage, add evening retinoid if tolerated, and ensure consistent application amount.
- No change after 12 weeks: Consider azelaic acid addition, dermatologist-guided options (e.g., hydroquinone cycles, tranexamic acid), or device-based care.
Safety and who should avoid
Topical safety.
Liquiritin is generally well tolerated on skin. Possible reactions include mild burning, redness, or dryness, especially when layered with exfoliants or retinoids. Patch-test new products on the forearm for 48 hours before facial use.
Oral safety (nuanced).
- Liquiritin vs. glycyrrhizin: Liquiritin does not share glycyrrhizin’s cortisol-mimicking mechanism, but mixed “licorice” extracts may still contain glycyrrhizin. Chronic high intake of glycyrrhizin can raise blood pressure and lower potassium.
- Doses: Because human oral data for purified liquiritin are limited, stay within conservative ranges (e.g., 20–100 mg/day, up to 200 mg/day short-term if well tolerated).
- Drug interactions (licorice family): Licorice constituents can interact with diuretics, corticosteroids, antihypertensives, and digoxin via potassium shifts (glycyrrhizin-related). Purified, glycyrrhizin-controlled liquiritin reduces this risk but does not remove it if the product is not rigorously standardized.
Who should avoid unsupervised use.
- Pregnant or breastfeeding individuals (insufficient safety data for concentrated liquiritin).
- Hypertension, heart failure, chronic kidney disease, or electrolyte disorders—particularly if using any licorice-family product not proven low in glycyrrhizin.
- People on diuretics, digoxin, or corticosteroids, unless a clinician reviews the exact product and labs.
- Allergy to legumes in rare cases (licorice is in the Fabaceae family); discontinue with any signs of hypersensitivity.
Stop and seek medical care if you develop persistent headaches, swelling, muscle weakness, irregular heartbeat, marked fatigue, rash, or worsening pigmentation. For skin, pause actives if you develop irritant dermatitis, re-build the barrier with bland moisturizers, and restart slowly or switch vehicles.
Evidence snapshot and research gaps
Human data to know.
- Melasma (topical): Controlled clinical work shows that topical liquiritin improved epidermal melasma over several weeks with good tolerability when compared against vehicle. Comparative studies suggest 2–4% strengths perform best when paired with photoprotection.
- Comprehensive dermatology context: Reviews of topical melasma therapies list liquiritin among botanical options with supportive signals but emphasize the need for larger, longer RCTs and combination regimens.
- Oral outcomes: As of now, robust human oral trials for liquiritin monotherapy are scarce. Pharmacological reviews summarize broad preclinical benefits (antioxidant, neuroprotective, anti-inflammatory), but translation requires dose-finding RCTs.
Mechanistic and preclinical highlights.
- Neurobehavioral: In chronic-stress mice, liquiritin improved depressive-like behaviors, tempered neuroinflammation, and modulated NLRP3 signaling.
- Neuroprotection and microvasculature: Studies report protection of neuronal cells via antioxidant pathways and preservation of endothelial function under hypoxia/reoxygenation stress.
- Inflammation and airway models: Emerging work explores liquiritin’s role in dampening inflammatory kinases and oxidative stress in respiratory disease models.
What’s missing (and needed).
- Standardized oral trials defining dose–response, safety, and clinically meaningful endpoints (mood scales, quality of life, skin imaging).
- Head-to-head dermatology studies: liquiritin vs. hydroquinone, azelaic acid, and tranexamic acid, with split-face designs and long-term follow-up.
- Pharmacokinetics in humans: Bioavailability, metabolite mapping (liquiritigenin), and influence of the gut microbiome.
- Combination science: How liquiritin pairs with niacinamide, retinoids, or laser/peel modalities for pigmentary disorders.
Practical interpretation.
Use topical liquiritin as a gentle, evidence-informed option for melasma and tone support, anchored by sunscreen. Approach oral liquiritin as exploratory; select standardized, low-glycyrrhizin products, start low, and measure outcomes objectively.
References
- Topical liquiritin improves melasma 2000 (Clinical Trial)
- Pharmacological activities and pharmacokinetics of liquiritin 2022 (Review)
- Liquiritin Alleviates Depression-Like Behavior in CUMS Mice by Inhibiting NLRP3 Inflammasome Activation 2022 (Preclinical Study)
- The Protective Effect of Liquiritin in Hypoxia/Reoxygenation Injury of Brain Microvascular Endothelial Cells 2021 (Preclinical Study)
- Liquorice Toxicity: A Comprehensive Narrative Review 2023 (Safety Review)
Disclaimer
This article is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Consult a qualified clinician before starting liquiritin—especially if you are pregnant or breastfeeding; have high blood pressure, kidney disease, or electrolyte disorders; or take diuretics, digoxin, corticosteroids, or other prescription medications. For skin concerns like melasma, individualized care from a dermatologist, consistent sunscreen use, and a well-tolerated routine are essential. Stop any product and seek medical care if you experience worrisome symptoms or skin reactions.
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