# Osmanthus Flower (Osmanthus fragrans)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/osmanthus-flower
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-05
**Evidence Score:** 2 / 10
**Category:** Compound
**Also Known As:** Sweet Osmanthus, Fragrant Olive, Tea Olive, Gui Hua, 桂花, Sweet Olive, Osmanthus fragrans var. aurantiacus, Osmanthus fragrans var. thunbergii, Devilwood, Chinese Sweet Olive

## Overview

Osmanthus fragrans is an ornamental flowering plant whose petals and extracts contain astilbin, a dihydroflavonol glycoside, along with apigenin and luteolin, which collectively exert antioxidant effects by scavenging [reactive oxygen species](/ingredients/condition/antioxidant) and modulating [inflammatory](/ingredients/condition/inflammation) cytokine cascades. Research remains largely preclinical, with most mechanistic data derived from in vitro assays and rodent models rather than human clinical trials.

## Health Benefits

• [Antioxidant](/ingredients/condition/antioxidant) properties from astilbin and flavonoid compounds (preliminary evidence from preclinical studies only)
• [Anti-inflammatory](/ingredients/condition/inflammation) potential attributed to astilbin content (based on animal model research, no human trials)
• [Immunomodulatory](/ingredients/condition/immune-support) effects suggested by isolated compound studies (preclinical evidence only)
• Traditional use for respiratory support and cough relief (historical use over 2,500 years, no clinical validation)
• Potential lipid-modulating properties from terpenoid content (theoretical based on compound analysis, no clinical trials)

## Mechanism of Action

Astilbin, the primary bioactive dihydroflavonol in Osmanthus fragrans, inhibits NF-κB signaling by blocking IκB kinase phosphorylation, thereby reducing downstream transcription of [pro-inflammatory cytokine](/ingredients/condition/inflammation)s including TNF-α and IL-6. Flavonoid constituents such as apigenin and luteolin act as direct radical scavengers, donating hydrogen atoms to neutralize superoxide and hydroxyl radicals, and may upregulate endogenous [antioxidant](/ingredients/condition/antioxidant) enzymes including superoxide dismutase (SOD) and catalase via Nrf2 pathway activation. Isolated polysaccharide fractions from the flower have been shown in vitro to stimulate macrophage phagocytic activity, suggesting [immunomodulatory](/ingredients/condition/immune-support) potential through pattern recognition receptor engagement.

## Clinical Summary

No peer-reviewed human clinical trials specifically investigating Osmanthus fragrans flower extract as a supplement have been published as of early 2025, making evidence quality very low by standard grading systems such as GRADE. Preclinical studies in murine models of [inflammation](/ingredients/condition/inflammation) have demonstrated statistically significant reductions in paw edema and serum IL-6 concentrations following astilbin administration at doses of approximately 10–50 mg/kg body weight, but these results cannot be directly extrapolated to human dosing. In vitro [antioxidant](/ingredients/condition/antioxidant) assays using DPPH and ABTS radical scavenging methods report IC50 values for osmanthus ethanolic extracts in the range of 0.2–1.5 mg/mL, indicating moderate potency compared to reference standards like ascorbic acid. Consumers and clinicians should treat any health claims surrounding this ingredient as hypothesis-generating rather than clinically substantiated.

## Nutritional Profile

Osmanthus fragrans flowers contain primarily bioactive secondary metabolites rather than significant macronutrients, given their use in small culinary and medicinal quantities. Moisture content in fresh flowers is approximately 80-85%. Dry weight composition includes: carbohydrates (~60-65% of dry weight, primarily structural polysaccharides and small amounts of simple sugars), protein (~8-12% of dry weight, with limited amino acid profiling data), lipids (~3-5% of dry weight including trace essential fatty acids). Key bioactive compounds include: flavonoids (total flavonoid content approximately 15-30 mg/g dry weight), with identified compounds including rutin, quercetin, apigenin, luteolin, and kaempferol derivatives; polyphenols including astilbin (a flavanonol/dihydroflavonol); volatile aromatic compounds (0.1-0.5% of fresh weight) dominated by linalool oxide, beta-ionone, gamma-decalactone, dihydro-beta-ionone, and cis-linalool oxide, which are primary contributors to the characteristic apricot-peach aroma; carotenoids including beta-carotene and lutein at trace levels (~0.5-2 mg/100g dry weight) contributing to flower pigmentation. Micronutrients present in modest amounts include vitamin C (~10-20 mg/100g fresh weight, subject to processing degradation), potassium, calcium (~200-400 mg/100g dry weight), magnesium, and iron at trace levels. Dietary fiber contributes approximately 15-20% of dry weight. Bioavailability note: flavonoid bioavailability is moderate and highly dependent on preparation method; aqueous extracts (teas, infusions) yield higher polyphenol solubility than raw consumption; volatile aromatic compounds are heat-sensitive and significantly reduced during drying or high-temperature processing; astilbin bioavailability in humans has not been formally characterized in clinical studies.

## Dosage & Preparation

No clinically studied dosage ranges exist for Osmanthus fragrans flower as human trials have not been conducted. Available research does not specify standardized forms, extracts, or recommended doses. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Osmanthus fragrans flower is widely used as a food flavoring and tea ingredient in East Asian culinary traditions and is generally regarded as safe at culinary doses, but no formal toxicology studies or maximum tolerable intake data exist for concentrated supplemental extracts. Individuals with known allergies to plants in the Oleaceae family, which includes olive, lilac, and jasmine, should exercise caution due to potential cross-reactive allergenic proteins. No documented drug-drug interactions have been established in peer-reviewed literature; however, because astilbin may modulate NF-κB and [inflammatory pathway](/ingredients/condition/inflammation)s, theoretical interactions with immunosuppressant medications such as corticosteroids or calcineurin inhibitors warrant caution. Safety data for use during pregnancy or lactation is entirely absent, and avoidance of supplemental doses beyond food-level consumption is prudent for these populations.

## Scientific Research

No human clinical trials, randomized controlled trials, or meta-analyses on Osmanthus fragrans flower have been conducted according to available research. All current evidence is limited to phytochemical analysis identifying compounds like astilbin, ionones, and terpenoids, with biological activity data derived solely from preclinical animal models and in vitro studies.

## Historical & Cultural Context

In traditional Chinese medicine, Osmanthus fragrans flowers have been used for over 2,500 years primarily for treating cough, improving complexion, and as a fragrance in teas and foods. The flowers have been valued primarily for their aromatic properties in East Asian cultural systems rather than as a medicinal herb.

## Synergistic Combinations

Green tea, Chrysanthemum flower, Jasmine, Rose petals, Honeysuckle

## Frequently Asked Questions

### What is astilbin and why is it important in osmanthus flower?

Astilbin is a dihydroflavonol-3-O-rhamnoside glycoside and the primary pharmacologically studied compound isolated from Osmanthus fragrans petals. It is structurally distinct from common flavonols due to its dihydro configuration, which enhances its binding affinity to inflammatory pathway proteins including IκB kinase, making it the main candidate behind the flower's reported anti-inflammatory activity in preclinical research.

### Is there any human clinical trial evidence for osmanthus flower supplements?

As of early 2025, no published randomized controlled trials or observational human studies have evaluated Osmanthus fragrans flower extract as a dietary supplement for any health outcome. All mechanistic and efficacy data originate from in vitro cell culture experiments and rodent animal models, which means the evidence is classified as very low quality and cannot confirm benefit or optimal dosing in humans.

### What dose of osmanthus flower extract is typically used in studies?

Preclinical animal studies have administered astilbin-rich osmanthus extracts at doses ranging from 10 to 50 mg/kg body weight in mice and rats to produce measurable anti-inflammatory effects. Direct conversion to a human equivalent dose using standard FDA allometric scaling would suggest roughly 1–4 mg/kg for an average adult, but no clinical validation of any dosage exists, and no supplement manufacturer dose has been confirmed as safe or effective through human trials.

### Can osmanthus flower supplements interact with medications?

No clinically documented drug interactions for osmanthus flower extract have been reported in peer-reviewed pharmacological literature. However, because astilbin suppresses NF-κB-mediated immune signaling, concurrent use with immunosuppressants such as tacrolimus, cyclosporine, or systemic corticosteroids is theoretically concerning and warrants medical consultation. Additionally, any flavonoid-rich extract has a theoretical potential to inhibit cytochrome P450 enzymes involved in drug metabolism, though this has not been specifically demonstrated for osmanthus constituents.

### Is osmanthus flower safe during pregnancy?

There are no published safety studies examining osmanthus flower extract during pregnancy or breastfeeding, making it impossible to establish a risk profile for these populations. While the flower is consumed in small quantities as a tea or food flavoring in traditional Asian diets without widely reported adverse effects, concentrated supplemental extracts represent a meaningfully higher dose exposure. Out of precaution, pregnant and lactating individuals should avoid supplemental forms of osmanthus extract until adequate safety data are available.

### What forms of osmanthus flower supplements are available, and which has the best absorption?

Osmanthus flower supplements are available as dried flower tea, standardized extracts, and concentrated powders. Standardized extracts that specify astilbin content may offer more consistent bioavailability compared to whole dried flowers, though no human absorption studies directly compare these forms. The extraction method and solvent used can significantly affect which flavonoid compounds are concentrated in the final product.

### Can I get osmanthus flower benefits from consuming it as food or tea rather than taking a supplement?

Osmanthus flowers are traditionally consumed as tea in Asian cuisines and may provide some bioactive compounds through dietary intake. However, the concentration of active constituents like astilbin in culinary doses of osmanthus tea has not been quantified in human studies, making it unclear whether food amounts provide the same effects observed in supplement research. Supplemental extracts are standardized to higher concentrations than what typically appears in food preparations.

### Who should consider osmanthus flower supplementation, and who should avoid it?

Osmanthus flower may be of interest to individuals seeking traditional respiratory support, though robust human evidence for this use is lacking. Those taking blood thinners or immunosuppressive medications should consult a healthcare provider before use, as the immunomodulatory and potential antiplatelet properties suggested by preclinical studies have not been ruled out in humans. Individuals with known allergies to plants in the Oleaceae family should exercise caution.

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