Spearmint leaf

Spearmint Leaf (Mentha spicata L.): A Comprehensive Encyclopedic Reference

1. Identity: Botanical Classification, Nomenclature, and Common Forms

1.1 Botanical and Taxonomic Identity

Spearmint (Mentha spicata), also known as garden mint, common mint, lamb mint, and mackerel mint, is native to Europe and southern temperate Asia, extending from Ireland in the west to southern China in the east. It is naturalized in many other temperate parts of the world, including northern and southern Africa, North America, and South America. Spearmint is a flowering, aromatic herb or groundcover in the Lamiaceae (mint) family.

Mentha spicata was first described scientifically by Carl Linnaeus in 1753. The species and its subspecies have many synonyms, including Mentha crispa, Mentha crispata, and Mentha viridis. Mentha spicata is thought to be an allopolyploid derived from M. longifolia and M. suaveolens.

Spearmint gets its common name from its spear-shaped (lanceolate) leaves, and the Latin word spicata refers to its floral spikes.

1.2 Morphological Description

Spearmint is a perennial herbaceous plant. It is 30–100 cm tall, with variably hairless to hairy stems and foliage, and a wide-spreading fleshy underground rhizome from which it grows. It is an aromatic herb with erect, square-shaped stems and narrow, oval-shaped leaves that have pointed tips and toothed edges. The leaves are arranged in opposite pairs and the small, pink, light purple, or white flowers appear in spikes. Spearmint flowers in the summer, from July to September in the northern hemisphere.

1.3 Common Preparations and Dosage Forms

Spearmint leaf is commercially available in several distinct forms, each with different constituent profiles and intended uses:

• Herbal tea (tisane): Mentha leaves, stems, and flowers have traditionally been used to add flavors and fragrance to herbal teas and spices in many dishes.
• Dried leaf: Fresh and dried spearmint are also used in foods and beverages.
• Essential oil (oil of spearmint): The aromatic oil, called oil of spearmint, is also used as a flavoring and sometimes as a scent.
• Standardized aqueous (polyphenol-rich) extract: Proprietary extracts standardized to rosmarinic acid content have been studied in clinical trials for cognitive and joint-related outcomes, typically delivered in capsule form.
• Topical application: To relieve muscle or joint pain, spearmint essential oil can be mixed with a carrier oil and rubbed into the skin.

Spearmint has significant economic value as a flavoring in chewing gum, in tea, and as an essential oil crop. Alongside its extensive use in cooking, spearmint is also found in many everyday products, including mouthwash, toothpaste, and chewing gum.

2. Traditional and Historical Use

2.1 Ancient and Classical Civilizations

Ancient Romans valued spearmint for its ability to "stir up the mind," and it was commonly used in baths to soothe sore limbs. The Roman writer Pliny the Elder recorded spearmint's stimulating and culinary uses; Pliny wrote in his Natural History that mint stirs the mind and the appetite, and Roman cooks built sauces around it that survive in Mediterranean cooking today.

2.2 Medieval and Renaissance Europe

In medieval times, spearmint was a staple herb in monastery gardens, used for its digestive benefits and its pleasant aroma. It is thought that the Romans introduced the mint plant to England before the 15th century, and current etymology traces the word back to Old English around the 8th century. Spearmint and other species of mint have been used in many different ways through time, including perfumes, early forms of toothpaste, and to help stabilize milk prior to refrigeration; it is often noted as being used to welcome guests by taking crushed leaves and strewing them around a gathering space or in a visitor's bath.

2.3 Traditional Iranian Medicine

Spearmint has been used in traditional Iranian medicine since ancient times for the management of diarrhea, as an antidote, for indigestion, intestinal weakness, abdominal pain, cold, influenza, sinusitis headache, and flatulence. In traditional Iranian medicine, spearmint has been prepared in a variety of ways — including tinctures, pills, and decoctions — to alleviate flatulence.

2.4 Moroccan and North African Traditions

Ethnobotanical studies have documented spearmint being used for many common health problems, including digestive issues, burns, headaches, pregnancy concerns, infections, and hypertension, and spearmint is the most commonly used herb in Morocco.

2.5 Asian Traditions

Additionally, in Nepal, spearmint has been chewed in raw form to address diarrhea and stomach aches. Besides internal applications, spearmint has also been used externally, with its use as a hair tonic noted in Iraq. In Asia, spearmint is grown in China, Japan, and India, where it is utilized in traditional cookery and medicine.

2.6 The Americas

European settlers brought spearmint to North America in the 17th century. In Colombia, the stems and leaves of the spearmint plant are used to relieve stomach aches.

2.7 Overarching Traditional Indications

In addition to traditional food flavoring, M. spicata is well known for its traditional medicinal uses, particularly for the treatment of cold, cough, asthma, fever, obesity, jaundice, and digestive problems.

3. Key Constituents and Active Compounds

3.1 Essential Oil (Volatile) Fraction

The essential oil of spearmint is the most commercially exploited fraction of the plant. Among the monoterpenes, carvone (22–73%) and limonene (8–31%) are the dominant constituents. Further essential oil components identified in the plant include piperitone, menthol, myrcene, beta-pinene, linalool, and caryophyllene.

Carvone is the signature compound that distinguishes spearmint from peppermint. Unlike peppermint, which is dominated by menthol, spearmint's comparatively low menthol and high carvone content gives it a sweeter, milder minty character. Head space solid-phase microextraction coupled with gas chromatography-mass spectrometry identified volatile molecules in spearmint belonging to different chemical classes, including p-cymene, isopiperitone, piperitone, dihydroedulan II, menthone, p-cymen-8-ol, and β-linalool.

3.2 Phenolic (Non-Volatile) Fraction

Phenolic compounds in spearmint have been analysed by ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry, and a total of 66 compounds were tentatively identified — the widest phenolic characterisation of spearmint to date. The analysis suggests the extract is composed of rosmarinic acid and its derivatives (230.5 ± 13.5 mg/g) with smaller amounts of salvianolic acids, caffeoylquinic acids, hydroxybenzoic acids, hydroxycinnamic acids, flavones, and flavanones.

Previous research has demonstrated that the primary phenolic metabolites are caffeic acid and rosmarinic acid. Additionally, the plant contains other compounds such as p-coumaric acid, cinnamic acid, ferulic acid, gallic acid, oleanolic acid, sinapic acid, phloretic acid, and vanillic acid, among others.

The contents of phenolic compounds in spearmint oil include 8.9 mg/100 g for caffeic acid, 1,344 mg/100 g for rosmarinic acid, and 16.8 mg/100 g for luteolin.

Among the classes of identified polyphenolic compounds in spearmint, rosmarinic acid derivatives and salvianolic acids are the most prevalent. Different flavones, flavanones, flavonols, phenolic acids, and lignans were also detected.

3.3 Chemotype Variation

The constituent profile of spearmint varies substantially depending on growing conditions, geographic origin, and cultivar. Mentha spicata shows variation in leaf blade dimensions, prominence of leaf veins, and pubescence. Specialized high-rosmarinic acid (Hi-RA) clonal lines have been developed for research and commercial purposes: the chemical fingerprints of Hi-RA spearmint clonal lines clearly differentiate them from commercial spearmint and they should be considered distinct clonal lines with potential health-promotive properties associated with higher levels of rosmarinic acid.

3.4 Mechanisms of Action of Key Constituents

Rosmarinic acid is the dominant non-volatile bioactive constituent. Rosmarinic acid is known to exert anti-inflammatory activities mainly due to its ability to inhibit lipoxygenases and cyclooxygenases, but it has also been shown to have anti-acetylcholinesterase and antioxidant activities.

Regarding the anti-androgenic mechanism: Spearmint contains phenolic compounds that appear to exert anti-androgenic effects through two primary mechanisms — inhibition of 5-alpha reductase, the enzyme that converts regular testosterone into its more potent form dihydrotestosterone (DHT), which is the same target as pharmaceutical anti-androgens like finasteride — and direct inhibition of androgen synthesis in the ovaries through effects on the cytochrome P450 3A4 enzyme pathway.

Regarding acetylcholinesterase (AChE) inhibition relevant to cognition: Decoctions of Mentha spicata leaves have been used as folk medicine to treat various neurological disorders. Aqueous and methanol extracts of M. spicata leaves possess AChE inhibitory activity. In another study, infusion of M. spicata leaves after gastrointestinal digestion was examined for AChE inhibitory activity; eriocitrin and eriodictyol were identified as the main chemical constituents responsible for its biological activities.

4. Scientific Evidence by Area of Use

4.1 Hormonal Modulation: Anti-Androgenic Effects and PCOS

This is the area with the strongest and most direct human clinical evidence for spearmint leaf. The evidence base rests principally on two randomized controlled trials conducted in women with polycystic ovary syndrome (PCOS) and/or hirsutism.

Trial 1 (Akdoğan et al., 2007 — Turkey, 5-day pilot): 21 women with hirsutism (12 with PCOS, 9 with idiopathic hirsutism) consumed spearmint tea twice daily for 5 days during the follicular phase of their cycle. The result was a significant reduction in free testosterone and significant increases in LH, FSH, and estradiol. Total testosterone was not significantly reduced in this shorter trial.

Trial 2 (Grant, 2010 — two-centre, 30-day RCT): This was a two-centre, 30-day randomized controlled trial. Forty-two volunteers were randomized to take spearmint tea twice a day for a one-month period and compared with a placebo herbal tea. At 0, 15, and 30 days, serum androgen hormone levels and gonadotrophins were checked, the degree of hirsutism was clinically rated using the Ferriman-Galwey score, and a questionnaire (the modified DQLI = Dermatology Quality of Life Index) was used to assess improvements in self-reported hirsutism.

The trial demonstrated that the use of spearmint herbal tea has significant measurable anti-androgen effects in patients with hirsutism due to PCOS. The authors predicted that had the patients continued the treatment for a longer period of time, the reductions in androgen hormone levels would have translated into improvements in the Ferriman-Galway objective ratings of hirsutism, as suggested by improvements in the DLQI scores.

There was no significant reduction in the objective Ferriman-Galwey ratings of hirsutism between the two trial groups over the trial duration (p = 0.12). There was, however, a clear and significant alteration in the relevant hormone levels, which was associated clinically with a reduction in self-reported degree of hirsutism but not with the objectively rated score. It was demonstrated and confirmed that spearmint has antiandrogen properties; the simple fact that this does not clearly translate into clinical practice is due to the relationship between androgen hormones and follicular hair growth and cell turnover time. Simply put, the study duration was not long enough.

Meta-analytic context: A meta-analysis of herbal teas in PCOS found that spearmint tea, alongside green tea and marjoram, significantly increased FSH levels and had potential androgen-lowering effects — though larger, longer trials are needed to draw firm conclusions on all outcomes.

Larger 2024 RCT: A randomized controlled trial involving 150 participants, divided equally between PCOS-diagnosed individuals and a non-PCOS control group, had subjects consume spearmint tea twice daily over a span of 12 weeks. The observed reductions in androgen levels following spearmint tea consumption underscore its promise as a complementary approach in managing androgen excess, warranting continued investigation into its therapeutic applications.

Evidence characterization: Spearmint has the strongest clinical evidence for PCOS specifically — it is the only tea with two randomized controlled trials testing androgen reduction in women with the condition. Nonetheless, the honest limitation here is that the total body of research is small. The landmark trial included only 42 women over one month. No large-scale, long-term study has tracked what happens with six months or a year of daily spearmint tea. There is no data on whether the anti-androgenic effect plateaus over time, reverses after stopping, or varies depending on PCOS phenotype. The studies have also not measured effects on ovulation rates or fertility outcomes directly.

4.2 Cognitive Function and Memory

Clinical evidence for cognitive effects of spearmint comes from a specific proprietary polyphenol-rich aqueous extract standardized to rosmarinic acid, investigated in adults with age-associated memory impairment (AAMI). This evidence should not be extrapolated to standard commercial spearmint tea without further study.

Pilot study (Nieman et al., 2014): Cognitive function task scores suggested improved reasoning (24.7 vs. 33.4 points; P = 0.023), attention/concentration (18.0 vs. 40.5 points; P = 0.002), and planning (29.8 vs. 44.1 points; P = 0.088) from baseline after 30 days of treatment. On day one, subjects also experienced acutely improved attention/concentration from pre-supplementation vs. 2 h (63.4 vs. 82.4 points, P = 0.042) and 4 h (63.4 vs. 92.5 points, P = 0.001). These results suggest the extract was well-tolerated and may improve certain aspects of cognitive function, and a further investigation in a randomized, controlled trial was indicated.

Pivotal double-blind RCT (Herrlinger et al., 2018): The purpose of this study was to investigate the effects of supplementation with a spearmint (Mentha spicata L.) extract, high in polyphenols including rosmarinic acid, on cognitive performance, sleep, and mood in individuals with age-associated memory impairment (AAMI). Subjects with AAMI (N = 90; 67% female; age = 59.4 ± 0.6 years) were randomly assigned (n = 30/group) to consume 900, 600, or 0 mg/day (two capsules, once daily) spearmint extract for 90 days, in this double-blind, placebo-controlled trial. Results showed that quality of working memory and spatial working memory accuracy improved after supplementation with 900 mg/day spearmint extract by 15% (p = 0.0469) and 9% (p = 0.0456), respectively, versus placebo.

Evidence characterization: The cognitive evidence is preliminary but methodologically sound for the studied population and specific extract. The findings are limited in generalizability: the extract used (a high-rosmarinic acid clonal line) differs compositionally from standard commercial spearmint. The trial was conducted in a non-demented population with subjective memory complaints; it does not establish effects in healthy adults or in clinical dementia. Industry funding should be noted as a limitation.

4.3 Joint Pain and Osteoarthritis

A clinical study found that the consumption of a high-rosmarinic acid spearmint tea for 16 weeks significantly decreased pain scores in patients with knee osteoarthritis (OA) compared to the consumption of a commercially available spearmint tea. The use of a high-rosmarinic acid variant as the active arm — compared to a standard spearmint control rather than an inert placebo — is an important design consideration when interpreting the magnitude of effect.

People can apply spearmint oil to the skin to help reduce joint pain. A 2017 review concluded that applying spearmint oil to the skin was a safe and effective way to help relieve pain, particularly in people with osteoarthritis, possibly due to its high carvone, limonene, and menthol concentrations.

Evidence characterization: The OA evidence is limited to small trials using specialized high-rosmarinic acid spearmint preparations rather than standard leaf products. The topical evidence derives from a review of multiple preparations and is not specific to spearmint alone. Larger, independently funded trials are needed before firm conclusions can be drawn.

4.4 Anti-Inflammatory Effects

Spearmint is a Mediterranean plant used as an aromatic agent, and studies have mainly focused on the essential oil, suggesting anti-inflammatory activity. In animal work, a spearmint phenolic extract was administered to rats in a paw oedema model (induced by carrageenan) and to mice in a TNBS-induced colitis model, in parallel with studies using HT-29 colorectal cancer cells. Administration of the extract led to reduced paw inflammation, reduction of colon injury and inflammation, with attenuation of histological markers, and reduction of iNOS expression. It repressed the in vitro movement of HT-29 cells in a wound healing assay. These findings suggest that spearmint extract exhibits acute and chronic anti-inflammatory activity and is able to inhibit migration of cancer cells, suggesting a potential role in supplementary therapy of IBD patients.

In vitro work showed that both spearmint and peppermint oils significantly inhibited (p < 0.05) IL-1β and TNF-α secretion from LPS-stimulated macrophages. Spearmint and peppermint oils also exhibited strong antioxidant activities in DPPH and reducing power assays, and both mint oils dose-dependently inhibited the growth of ETEC F18+ in vitro.

Evidence characterization: Anti-inflammatory evidence is primarily preclinical (animal models and in vitro cell studies). No adequately powered human RCTs have directly evaluated spearmint for inflammatory conditions as a primary endpoint.

4.5 Digestive and Gastrointestinal Applications

Traditional use of spearmint for digestive complaints — including nausea, flatulence, indigestion, and bowel discomfort — has a long cross-cultural history but limited formal clinical investigation as a stand-alone intervention in humans. Traditional uses specifically included treatment of cold, cough, asthma, fever, obesity, jaundice, and digestive problems. Mint oils' therapeutical activities can be considered in the treatment of various diseases, such as digestive disorders, diarrhea, intestinal inflammation, and nervous system disorders.

Evidence characterization: Most clinical evidence for mint in gastrointestinal conditions pertains to peppermint oil, which has a distinct chemical profile (dominated by menthol). Human clinical data specifically for spearmint leaf in gastrointestinal conditions are sparse. Preclinical data are supportive, and traditional use is extensive, but claims require further human investigation.

4.6 Antioxidant Activity

M. spicata exhibited, according to some studies, promising antioxidant, antidiabetic, anti-inflammatory, and anticancer effects, which show its potential to be used as a source for identifying natural drugs against cellular oxidative stress and its related diseases. The antioxidant activity is attributed primarily to the high rosmarinic acid and flavonoid content of the leaf.

Evidence characterization: Antioxidant activity is well established in vitro and in animal studies but has not been systematically evaluated as a clinical endpoint in human trials. In vitro DPPH radical scavenging assays and reducing power assays are not directly predictive of clinical benefit in humans.

4.7 Antimicrobial and Antifungal Activity

Like other species of mint, spearmint has antifungal properties, and it may be useful in treating fungal infections resistant to antifungal medications. A 2023 laboratory study found that mint essential oil prevented the growth of three species of fungus, including Candida albicans, the fungus that most commonly causes vaginal yeast infections.

Evidence characterization: Antimicrobial evidence is exclusively preclinical (in vitro). There are no published human trials evaluating spearmint as a treatment or prophylactic agent for microbial or fungal infections.

5. Body Systems and Health Areas of Association

• Endocrine/Reproductive System: Anti-androgenic effects in PCOS and hirsutism (two RCTs; strongest human evidence).
• Central Nervous System / Cognition: Working memory and attention in age-associated memory impairment (one double-blind RCT with a proprietary extract).
• Musculoskeletal System: Joint pain and osteoarthritis, both via ingested high-rosmarinic acid tea and topical essential oil preparations (limited clinical evidence).
• Gastrointestinal System: Digestive support, antispasmodic, carminative, and anti-inflammatory effects (strong traditional use; preclinical support; limited human data).
• Immune/Inflammatory Pathways: Inhibition of inflammatory cytokines IL-1β and TNF-α (in vitro and animal data only).
• Oral Health: Spearmint is found in many everyday products including mouthwash and toothpaste, traditionally used for oral hygiene and breath freshening.
• Antioxidant Defense: Free radical scavenging attributed to rosmarinic acid, luteolin, and flavonoid content (in vitro data).

6. Dosage Forms and Dosages Reported in Studies

The following dosages are reported directly from the cited clinical studies and should not be interpreted as recommendations:

• Spearmint herbal tea (hormonal/PCOS): Spearmint tea has most often been used at two cups daily for up to 16 weeks in the available clinical trials. The 5-day pilot used twice-daily tea, and the 30-day RCT used two cups per day.
• Proprietary polyphenol-rich spearmint extract (cognitive/memory): Subjects were randomly assigned to consume 900, 600, or 0 mg/day (two capsules, once daily) spearmint extract for 90 days in the pivotal RCT. Spearmint extract has most often been used by adults at a dose of 900 mg by mouth daily for up to 90 days.
• Spearmint tea (osteoarthritis): A high-rosmarinic acid spearmint tea was consumed for 16 weeks in the knee OA trial, though specific per-cup quantities of rosmarinic acid were not reported in the available abstracts.
• Safety evaluation doses (animal studies): Although there were no treatment-related adverse effects at any of the doses tested (0, 422, 844, and 1948 mg/kg body weight/day), the ingestion of greater than 844 mg/kg body weight/day caused significant and dose-dependent increases in the absolute and relative weights of the pituitary glands in male rats and thyroid glands in male and female rats.
• Human safety study: Ingestion of both 600 and 900 mg/day for 90 days had no effect on plasma levels of follicular stimulating hormone, luteinizing hormone, or thyroid stimulating hormone, or other safety parameters including vital signs, plasma chemistry, or whole blood hematology values.

7. Safety Considerations and Known Interactions

7.1 Regulatory Status

Spearmint (Mentha spicata L.) and spearmint extracts are Generally Recognized as Safe (GRAS) for use as flavoring agents in beverages, pharmaceuticals, and confectionaries under 21 CFR 182 and 21 CFR 182.20. This GRAS designation applies to use as a flavoring, not as a therapeutic agent at supplemental doses.

7.2 Genotoxicity

The Ames test revealed no indication of mutagenicity for spearmint essential oil. The safety of a dry spearmint extract was also examined through chromosomal aberration testing as part of a broader 90-day subchronic toxicity study.

7.3 Potential Hepatotoxic and Nephrotoxic Signals (Animal Data)

Animal data on high-dose spearmint have produced conflicting signals. There are a few studies that examine the safety of spearmint, and in these rodent studies carried out with an unstandardized spearmint tea using the same spearmint preparation, spearmint was reported to cause uterine toxicity and be nephrotoxic and hepatotoxic. However, horses fed high-rosmarinic acid spearmint (about 68 g rosmarinic acid per gram dry weight of leaf tissue) for 24 days in a randomized double-blind controlled study design showed no indications of any negative effects on feed and water intake, fecal consistency, general viability, blood chemistry, or hematology. Studies of spearmint extracts in humans and animals have reported conflicting results with respect to toxicity. Since the chemical composition of these extracts was not always reported and the spearmint source material was different, the relevance of existing data for evaluating the risks associated with ingestion of a dried aqueous spearmint extract standardized to rosmarinic acid is not fully clear.

In human studies at supplemental doses: Ingestion of both 600 and 900 mg/day of a standardized dried aqueous spearmint extract for 90 days had no effect on plasma levels of follicular stimulating hormone, luteinizing hormone, thyroid stimulating hormone, or other safety parameters including vital signs, plasma chemistry, or whole blood hematology values.

7.4 Potential Organ-Weight Changes at Very High Animal Doses

At doses greater than 844 mg/kg body weight per day in rats, significant and dose-dependent increases were observed in the absolute and relative weights of the pituitary glands in males and thyroid glands in males and females. Significant increases in relative weights of the hearts and livers of male rats and salivary glands in female rats were observed at 1948 mg/kg body weight per day. These doses are far in excess of any doses used in human clinical trials.

7.5 Drug Interactions

Some medications can harm the liver, and taking spearmint along with a medication that can also harm the liver might theoretically increase the risk of liver damage. Spearmint may cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing, and taking spearmint with sedative medications might theoretically cause breathing problems and/or excessive sleepiness.

The anti-androgenic effects observed in PCOS studies are pharmacologically significant and mean that spearmint may interact with hormone-modulating medications, including oral contraceptives and anti-androgen drugs, in ways that have not been systematically studied.

7.6 Allergy and Hypersensitivity

Topical spearmint may cause an allergic reaction in some people, but this is rare. Cross-reactivity with other Lamiaceae plants is plausible but has not been formally evaluated in published clinical literature.

7.7 Distinction from Peppermint

Despite the similar names, spearmint (Mentha spicata) and peppermint (Mentha × piperita) are different plants with different phytochemical profiles. Only spearmint has anti-androgen RCT evidence in PCOS. Peppermint is a hybrid derived in part from spearmint and water mint (Mentha aquatica) and is dominated by menthol rather than carvone. Safety and efficacy data for one should not be assumed to apply to the other.

References

• Mahendran G. et al. (2021). The traditional uses, phytochemistry and pharmacology of spearmint (Mentha spicata L.): A review. Journal of Ethnopharmacology, 278, 114266. PubMed.
• Medicinal Uses, Phytochemistry, Pharmacology, and Toxicology of Mentha spicata — PMC (2022)
• Phenolic and Volatile Composition of a Dry Spearmint (Mentha spicata L.) Extract — PMC / Molecules (2018)
• Herrlinger KA et al. (2018). Spearmint Extract Improves Working Memory in Men and Women with Age-Associated Memory Impairment. Journal of Alternative and Complementary Medicine. PMC.
• Grant P. (2010). Spearmint herbal tea has significant anti-androgen effects in polycystic ovarian syndrome. A randomized controlled trial. Phytotherapy Research.
• Lasrado JA et al. (2017). Safety and tolerability of a dried aqueous spearmint extract. Regulatory Toxicology and Pharmacology, 86, 167–176.
• The safety of a dry spearmint extract in vitro and in vivo. Regulatory Toxicology and Pharmacology (2014). ScienceDirect.
• Reduction of Inflammation and Colon Injury by a Spearmint Phenolic Extract in Experimental Bowel Disease in Mice. PMC (2019).
• Mint Oils: In Vitro Ability to Perform Anti-Inflammatory, Antioxidant, and Antimicrobial Activities and to Enhance Intestinal Barrier Integrity. PMC / Antioxidants (2021).
• Androgen Modulation Through Spearmint Tea: Exploring Effects in PCOS and Non-PCOS Populations. Journal of the Academy of Nutrition and Dietetics (2024).
• Association of Herbal Tea and FSH, Anthropometric Parameters, and Fasting Blood Glucose in PCOS Women: A Systematic Review and Meta-Analysis. Clinical Nutrition Research (2024).
• High-Rosmarinic Acid Spearmint Tea in the Management of Knee Osteoarthritis Symptoms. PMC.
• Differences in the chemotype of two native spearmint clonal lines selected for rosmarinic acid accumulation. Industrial Crops and Products (2014). ScienceDirect.
• Spearmint (Mentha spicata L.) Phytochemical Profile: Impact of Pre/Post-Harvest Processing and Extractive Recovery. PMC (2022).
• Spearmint — Wikipedia (botanical and taxonomic overview)
• Spearmint — Royal Botanic Gardens Kew
• Mentha spicata — NC State Extension Gardener Plant Toolbox
• A randomised clinical trial of the effects of spearmint herbal tea on hirsutism in females with PCOS. Endocrine Abstracts, SFEBES 2008.