--- topic: "Spearmint" title: "Hormones, Memory, and Anti-Inflammatory Support" order: 1 description: "How spearmint tea and extract lower excess androgens in PCOS, improve working memory in older adults, and reduce inflammation through rosmarinic acid and carvone" question: "Does spearmint tea help PCOS symptoms, memory and joint pain?" answer: "Spearmint tea likely lowers free testosterone in PCOS; memory and knee-pain benefits each rest on a single small trial." actions: - "Drink two cups of spearmint tea daily (1–2 teaspoons dried leaf per cup, steeped 5–10 minutes), as in the PCOS trials [1][2]." - "Allow weeks to months: hormone changes appeared in 30 days, but hair-growth changes take at least 3–6 months [2]." - "Use spearmint, not peppermint, which has no documented anti-androgen effect; the memory trial used 900 mg a day of a standardized extract [3]." cautions: - "Very high doses of spearmint oil (not tea) should be avoided in pregnancy." - "Use spearmint tea alongside, not instead of, conventional PCOS treatment; objective hair growth did not change significantly in 30 days [2]." - "In theory, frequent heavy drinking could lower testosterone in men; this has not been studied at two cups a day." confidence: 3 confidenceNote: "Two small hormone trials (21 and 42 women, 30 days), a 90-person memory RCT (patented extract), and a 62-person knee trial without placebo." evidenceSummary: rctCount: 4 metaAnalysisCount: 0 totalParticipants: "~215" replicated: true newestStudyYear: 2021 references: - id: "1" pmid: "17310494" title: "Effect of spearmint (Mentha spicata Labiatae) teas on androgen levels in women with hirsutism" authors: "Akdogan M, Tamer MN, Cure E, Cure MC, Koroglu BK, Delibas N" year: 2007 journal: "Phytotherapy Research" - id: "2" pmid: "19585478" title: "Spearmint herbal tea has significant anti-androgen effects in polycystic ovarian syndrome. A randomized controlled trial" authors: "Grant P" year: 2010 journal: "Phytotherapy Research" - id: "3" pmid: "29314866" title: "Spearmint Extract Improves Working Memory in Men and Women with Age-Associated Memory Impairment" authors: "Herrlinger KA, Nieman KM, Sanoshy KD, Fonseca BA, Lasrado JA, Schild AL, et al." year: 2018 journal: "Journal of Alternative and Complementary Medicine" - id: "4" pmid: "25058311" title: "High-Rosmarinic Acid Spearmint Tea in the Management of Knee Osteoarthritis Symptoms" authors: "Connelly AE, Tucker AJ, Tulk H, Catapang M, Chapman L, et al." year: 2014 journal: "Journal of Medicinal Food" - id: "5" pmid: "34201645" title: "Mint Oils: In Vitro Ability to Perform Anti-Inflammatory, Antioxidant, and Antimicrobial Activities and to Enhance Intestinal Barrier Integrity" authors: "Hejna M, Kovanda L, Rossi L, Liu Y" year: 2021 journal: "Antioxidants" --- Spearmint is a common herb found in kitchens and herb gardens worldwide, but it contains a surprisingly rich pharmacological toolkit. Two cups of spearmint tea per day have been shown in clinical trials to significantly reduce free testosterone in women dealing with unwanted hair growth from PCOS or hormonal imbalance. [1][2] A separate 90-day trial found that a spearmint extract improved working memory scores by 15% in adults experiencing age-related memory decline. [3] The mechanism behind both effects traces largely to rosmarinic acid — a polyphenol that inhibits androgens, protects neurons, and dampens inflammatory signaling — along with the essential oil compound carvone, which gives spearmint its characteristic mild sweetness. For such a familiar plant, the clinical evidence is unusually strong. ## How Spearmint Works Spearmint's health effects come from two main compound classes working through complementary pathways: **Rosmarinic acid** is a caffeic acid ester that spearmint produces in particularly high concentrations (roughly 10–15 times more than peppermint). It is a potent antioxidant, inhibits the COX-2 enzyme involved in prostaglandin production, and readily crosses the blood-brain barrier. In the brain, it inhibits acetylcholinesterase — the enzyme that breaks down acetylcholine — effectively raising levels of this key memory neurotransmitter. [3] **Carvone** is the main volatile compound that gives spearmint its distinctive scent (as opposed to the menthol that dominates peppermint). Research suggests carvone has anti-androgenic properties by interfering with androgen receptor binding and inhibiting 5-alpha reductase, the enzyme that converts testosterone to its more potent form DHT. [1] ### Anti-Androgenic Effects and PCOS The most clinically validated use of spearmint is reducing androgen excess in women. Polycystic ovarian syndrome (PCOS) is a hormonal condition affecting 10–15% of reproductive-age women, characterized by elevated androgens that cause symptoms including excess hair growth (hirsutism), acne, and irregular periods. The 2007 Akdogan trial studied 21 women with hirsutism, 12 of whom had confirmed PCOS. [1] Participants drank two cups of spearmint tea daily during the follicular phase of their menstrual cycle. At the end of the study period, free testosterone was significantly decreased while luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol were all significantly increased — a hormonal shift consistent with reduced androgen signaling. The effect was specifically on free (biologically active) testosterone rather than total testosterone, which matters clinically because free testosterone is what drives androgenic symptoms. The 2010 Grant randomized controlled trial extended this to 42 women with PCOS over 30 days. [2] The spearmint group showed clear and significant alterations in hormone profiles. Participants reported reduced subjective perception of hirsutism, though objective measures of hair growth (which change slowly over months) were not significantly different by the trial's end. The authors concluded that spearmint has meaningful anti-androgen properties and warrants further study as a non-pharmaceutical management strategy for PCOS. Practical implication: two cups of spearmint tea (using dried spearmint leaves steeped 5–10 minutes) per day appears to be the effective dose from these trials. This is distinct from peppermint, which has no documented anti-androgenic effect. ### Cognitive Function and Memory A 90-day double-blind, placebo-controlled trial enrolled 90 adults aged 50–70 with self-reported age-associated memory impairment. [3] Participants received 900 mg/day, 600 mg/day, or placebo of a high-rosmarinic acid spearmint extract (Neumentix, standardized to 14.5% rosmarinic acid). Cognitive testing at baseline, 30, 60, and 90 days assessed working memory, spatial memory, and sleep quality. The 900 mg/day group showed: - **15% improvement** in quality of working memory scores (p = 0.0469) - **9% improvement** in spatial working memory accuracy (p = 0.0456) - Significantly improved ability to fall asleep (p = 0.0046) The 600 mg/day group showed improvements in some secondary outcomes but not the primary memory endpoints, suggesting a dose-response relationship. The proposed mechanism is rosmarinic acid's dual action: inhibiting acetylcholinesterase (raising acetylcholine) and protecting neurons from oxidative stress that accumulates with age. ### Anti-Inflammatory Effects Spearmint's rosmarinic acid content gives it meaningful anti-inflammatory capacity. A 16-week randomized double-blind trial in 62 adults with knee osteoarthritis compared high-rosmarinic acid spearmint tea to regular spearmint tea. [4] The high-rosmarinic acid group experienced significantly greater reductions in pain and improvements in stiffness and physical function scores. In vitro, spearmint extract reduced LPS-induced prostaglandin E2 and nitric oxide production in cartilage explants, suggesting direct chondroprotective activity. In vitro studies on spearmint and peppermint oils confirm significant inhibition of IL-1β and TNF-α (two primary inflammatory cytokines) from activated immune cells, along with antioxidant activity across multiple assay methods and antimicrobial activity against a gut pathogen (enterotoxigenic E. coli). [5] ## Practical Use **As tea:** Use dried spearmint leaves (not peppermint, which has different compounds), 1–2 teaspoons per cup, steeped 5–10 minutes. Two cups daily is the dose studied in the anti-androgen trials. The tea is naturally caffeine-free and mild in flavor. **As extract:** The cognitive trial used 900 mg/day of a standardized spearmint extract (Neumentix). Look for products standardized to rosmarinic acid content, typically 14–15%. **For PCOS and hirsutism:** Spearmint tea is well-tolerated and may be used alongside conventional treatments. Hormonal effects develop over weeks to months — it is not a quick fix. It works best as part of a broader hormonal support strategy that may include reducing seed oils, managing blood sugar, and supporting liver detox of excess estrogens. See our [DIM page](/dim/estrogen-metabolism) and [PCOS page](/pcos/natural-management) for complementary approaches. **Safety:** Spearmint is considered safe at culinary and tea doses. Very high doses of spearmint oil (not tea) should be avoided in pregnancy. There are no known drug interactions at typical tea doses, though the anti-androgenic effect means it could theoretically reduce testosterone in men who drink it very frequently — this has not been studied as a concern at two cups/day. ## Evidence Review ### Anti-Androgenic Evidence: Two Human Trials **Akdogan et al. 2007 [1]** is a crossover-design pilot study in 21 women with clinical hirsutism. Spearmint tea (Mentha spicata) was consumed twice daily during the follicular phase. The key hormonal changes observed: - Free testosterone significantly decreased (p < 0.05) - LH significantly increased (p < 0.05) - FSH and estradiol significantly increased (p < 0.05) - Total testosterone showed a trend toward reduction but did not reach statistical significance The specificity of the free testosterone reduction is important. Free testosterone represents the biologically active fraction — roughly 1–3% of total testosterone in women — and is most closely linked to androgenic symptoms. An intervention that selectively reduces free testosterone while raising FSH and LH suggests a mechanism at the peripheral androgen-receptor level rather than central suppression of the HPG axis. The proposed mechanism involves carvone and related terpenes competitively inhibiting androgen receptor binding and blocking 5-alpha reductase. **Grant 2010 [2]** is the higher-quality trial: a two-centre randomized controlled trial with 42 women with PCOS. The spearmint group (n=21) drank spearmint herbal tea twice daily for 30 days; the control group (n=21) drank chamomile tea as a matched placebo herbal beverage. Results: - LH significantly increased in the spearmint group vs. control (p < 0.05) - FSH increased (p < 0.05) - Free and total testosterone both decreased, with free testosterone showing the larger effect (p < 0.05) - Self-reported hirsutism severity decreased on the Ferriman-Gallwey scale, though the objective visual scoring did not reach statistical significance after 30 days The authors noted that objectively quantified hair growth requires at least 3–6 months to show visible change, meaning the 30-day trial window was adequate for demonstrating hormonal effect but insufficient to detect downstream changes in hair density. A longer follow-up trial would be needed to fully assess clinical efficacy. Methodological strengths: active control (chamomile tea rather than no treatment), randomized allocation, multi-site recruitment. Limitation: no blinding (participants can taste the difference between chamomile and spearmint tea), no measurement of serum carvone levels to confirm intake, relatively small sample. ### Cognitive Function: 90-Day Double-Blind RCT **Herrlinger et al. 2018 [3]** is the most methodologically rigorous study in the spearmint literature. The trial enrolled 90 healthy adults (mean age 59.4 ± 0.6 years) with subjective age-associated memory impairment confirmed by the Memory Complaint Questionnaire. They were randomized to 900 mg/day Neumentix (n=30), 600 mg/day Neumentix (n=30), or placebo (n=30) for 90 days. Neumentix is a patented spearmint extract standardized to 14.5% total polyphenols, predominantly rosmarinic acid. Primary cognitive endpoints at day 90: - Quality of Working Memory subscale of the Stroop Test: **+15.0%** improvement in the 900 mg group vs. baseline, significantly greater than placebo (p = 0.0469) - Spatial Working Memory (Cambridge Neuropsychological Test Automated Battery): **+9.0%** accuracy improvement vs. baseline, significantly greater than placebo (p = 0.0456) Secondary outcomes in the 900 mg group: - Significantly improved ability to fall asleep (Leeds Sleep Evaluation Questionnaire, p = 0.0046) - Trend toward improved next-day alertness (p = 0.0562) The 600 mg group showed a trend toward improved secondary memory measures but did not reach significance on primary endpoints, consistent with dose-dependent effects. No adverse events were reported. The placebo group showed no improvement or slight decline across memory endpoints over 90 days, consistent with the age-associated memory impairment phenotype. Mechanistic hypothesis supported by the authors: rosmarinic acid inhibits acetylcholinesterase (confirmed in vitro at concentrations achievable through supplementation), crosses the blood-brain barrier (confirmed in animal studies), and reduces neuroinflammation through NF-κB suppression and prostaglandin inhibition. The sleep improvement may be mediated by separate pathways involving carvone's mild sedative properties. Limitations: single trial of one proprietary extract, no mechanistic biomarkers collected in the human study, the participant population self-selected for memory concerns. Independent replication is needed. ### Anti-Inflammatory: Osteoarthritis Trial **Connelly et al. 2014 [4]** conducted a 16-week randomized, double-blind parallel trial in 62 adults with radiographically confirmed knee osteoarthritis. Participants were assigned to high-rosmarinic acid spearmint tea (approximately 1.3 g rosmarinic acid per dose) or regular spearmint tea as an active comparator. This design (two active treatments rather than drug vs. placebo) tests whether rosmarinic acid content is the active variable. At 16 weeks, the high-rosmarinic acid group showed significantly greater reductions in: - WOMAC pain subscale (p < 0.05) - WOMAC stiffness subscale (p < 0.05) - Physical disability scores (p < 0.05) Ex vivo cartilage explant experiments confirmed that spearmint extract reduced LPS-stimulated prostaglandin E2 (PGE2) and nitric oxide (NO) production — both key mediators of joint inflammation and cartilage degradation. The authors proposed that rosmarinic acid acts as a COX-2 inhibitor and NF-κB suppressor, reducing PGE2 synthesis through multiple complementary pathways. Limitation: both arms received an active spearmint tea, making it impossible to assess the absolute effect against no treatment; only the differential effect of rosmarinic acid content was measured. ### Antioxidant and Antimicrobial Evidence **Hejna et al. 2021 [5]** is an in vitro comparative study of spearmint and peppermint essential oils, tested for anti-inflammatory effects in porcine alveolar macrophages, effects on intestinal barrier integrity in IPEC-J2 cells, antioxidant activity, and antimicrobial activity against enterotoxigenic E. coli (ETEC) F18+. Key findings relevant to spearmint: - Significant inhibition of IL-1β and TNF-α secretion from LPS-stimulated macrophages (p < 0.05) - Strong antioxidant activity in DPPH radical scavenging and reducing power assays (p < 0.05) - Dose-dependent inhibition of the growth of ETEC F18+ (p < 0.05) In vitro data cannot be directly translated to human clinical recommendations, as essential oil absorption and bioavailability at oral doses differs substantially from cell culture conditions. However, the authors themselves note that further research is needed to evaluate efficacy in vivo, so these results are only preliminary mechanistic support. ### Evidence Strength Summary | Indication | Best Evidence | Sample | Duration | Confidence | |---|---|---|---|---| | Anti-androgen / PCOS | 2 RCTs | 21–42 women | 30 days | Moderate | | Working memory | 1 double-blind RCT | 90 adults | 90 days | Moderate | | Osteoarthritis pain | 1 double-blind RCT | 62 adults | 16 weeks | Moderate | | Antioxidant / antimicrobial | In vitro only | — | — | Low (mechanistic) | **Overall assessment:** Spearmint is unusual among kitchen herbs in having multiple, well-designed human clinical trials across distinct indications. The anti-androgenic evidence is the strongest, with two independent trials showing consistent hormonal effects. The cognitive trial is the most rigorous methodologically and produces a clinically meaningful effect size. Anti-inflammatory evidence is supported by both a clinical osteoarthritis trial and mechanistic in vitro data. No serious adverse effects have been reported in any trial. The main gap is trial duration — longer studies (6–12 months) are needed to determine whether hormonal and cognitive benefits persist and whether hair growth outcomes change meaningfully.