This product is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the Food and Drug Administration.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before using herbs, especially if you are pregnant, nursing, taking medications, or have a medical condition.
Tectona grandis contains bioactive compounds including lapachol, tectol, and flavonoids that may help regulate blood glucose levels. These compounds are thought to enhance insulin sensitivity and potentially support pancreatic beta-cell function. The antidiabetic effects are attributed to antioxidant properties that reduce oxidative stress associated with diabetes complications. However, human clinical trials are limited, and the exact mechanism requires further research (Evidence Level C, preliminary studies).
Does Tectona grandis interact with diabetes medications?
Tectona grandis may potentially interact with antidiabetic medications, as both work to lower blood glucose levels. Combining them could cause additive effects leading to hypoglycemia (dangerously low blood sugar). Additionally, due to potential effects on liver enzymes, teak preparations may alter the metabolism of various pharmaceutical drugs. Patients taking insulin, metformin, or other glucose-lowering medications should consult a healthcare provider before using Tectona grandis products (Evidence Level C).
What is the recommended dosage of Tectona grandis bark?
The traditional Ayurvedic dosage for Tectona grandis bark is 5-10 grams prepared as a decoction (boiled extract), typically taken once or twice daily. For hair care, teak seed oil is applied topically to the scalp and massaged gently. Standardized commercial preparations may have different dosing recommendations. Due to limited clinical safety data, users should start with lower doses and avoid exceeding traditional recommendations without medical supervision (Traditional use, Evidence Level C).
Is Tectona grandis safe during pregnancy and breastfeeding?
Tectona grandis is considered unsafe during pregnancy and should be avoided. The active compounds, including lapachol and related naphthoquinones, have been associated with potential uterine stimulation and may pose risks to fetal development. There is insufficient safety data for breastfeeding women, so use during lactation is also not recommended. Women who are pregnant, planning pregnancy, or breastfeeding should consult a qualified healthcare practitioner before considering any teak-based preparations (Evidence Level D, theoretical concerns).
What are the benefits of Tectona grandis for hair growth?
Tectona grandis (teak) has been traditionally used in Ayurveda for promoting hair growth and treating scalp conditions. The seed oil is believed to strengthen hair follicles, reduce dandruff, and improve overall scalp health due to its antimicrobial and anti-inflammatory properties. Some traditional practitioners claim it helps prevent premature graying and hair loss. While these uses are well-documented in Ayurvedic texts, modern clinical studies validating these specific hair benefits are limited (Traditional use, Evidence Level C).
PubMed-compiled information sheet
This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.
Compiled from 30 PubMed articles · model: gemma4:31b
Summary
Tectona grandis, commonly known as teak, is a biologically valuable member of the Lamiaceae (mint) family used both as a high-value timber and in traditional medicine [PMID:29506390, PMID:40783105].
Background
Tectona grandis is a tropical timber tree renowned for its durability, strength, and resistance to termite and fungal damage [PMID:29506390, PMID:29800113].
Traditional uses
In traditional Dai medicine and other indigenous systems, it is used to treat malaria, inflammation, diabetes, liver disease, bronchitis, tumors, cholelithiasis, jaundice, skin disease, the common cold, headaches, scabies, and as an anti-helminthic [PMID:36978912, PMID:38151632, PMID:35280534].
Active compounds
Active constituents include naphthoquinones (such as lapachol and deoxylapachol), anthraquinones (such as 1-hydroxy-2,6,8-trimethoxy-9,10-anthraquinone and 2-methylanthraquinone), isoprenoid quinones, tectoquinone, triterpenoids, steroids, lignans, fatty esters, phenolic compounds, and diterpenoids [PMID:29506390, PMID:38151632, PMID:36323840, PMID:40733162]. Specific 5-alpha reductase inhibitors identified include (+)-eperua-8,13-dien-15-oic acid and (+)-eperua-7,13-dien-15-oic acid [PMID:35566245].
Mechanism of action
Tectona grandis leaf extracts exhibit inhibitory activity against steroid 5-alpha reductase (S5AR), which prevents the conversion of testosterone to dihydrotestosterone (DHT) [PMID:39474646, PMID:40733162]. Additionally, metabolites have been shown to modulate the NLRP3 inflammasome axis to alleviate neurological dysfunction [PMID:40783105].
Clinical evidence
Evidence BAndrogenic Alopecia
A hair tonic containing 1% teak leaf extract was evaluated for effectiveness and safety as a hair growth promoter in males [PMID:39474646]
Evidence DOxaliplatin-induced chemofog
Ethanol extract of T. grandis leaves and its nanoformulation alleviated neurological dysfunction in rats via modulation of the NLRP3 inflammasome axis [PMID:40783105]
Evidence DDiabetes Mellitus
Teak leaf ethanol extract was studied in diabetic rats for its effects on nitric oxide and malondialdehyde levels [PMID:37779332]
Safety & adverse effects
Tectona grandis is a potent sensitizer; exposure to teak dust can cause allergic contact eczema and severe itching [PMID:14459786]. Lapachol has been identified as one of the sensitizing agents in teak wood [PMID:14106137].
Evidence summary
The evidence consists primarily of review articles and preclinical animal or in vitro studies (Level C and D), with one randomized controlled trial (Level B) regarding hair growth.
PubMed sources
1.PMID: 29506390 (2019) — Tectona grandis (teak) - A review on its phytochemical and therapeutic potential. · Natural product research
2.PMID: 35280534 (2022) — Tectona grandis L.f: A comprehensive review on its patents, chemical constituents, and biological activities. · Saudi journal of biological sciences
3.PMID: 40783105 (2025) — Tectona grandis metabolites alleviate oxaliplatin-induced chemofog in rats: Modulation of the NLRP3 inflammasome axis. · Journal of ethnopharmacology
4.PMID: 14106137 (1964) — CONTACT ECZEMA CAUSED BY TRUE TEAK (TECTONA GRANDIS). A FOLLOW-UP STUDY OF A PREVIOUS EPIDEMIOLOGICAL INVESTIGATION, AND A STUDY INTO THE SENSITIZING EFFECT OF VARIOUS TEAK EXTRACTS. · British journal of industrial medicine
5.PMID: 37779332 (2023) — Effects of Tectona grandis L. Extract in Diabetic Rats on Nitric Oxide and Malondialdehyde Levels.
Government sources
No direct government monograph is available for this herb. The content below is AI-generated and has not been verified against an authoritative government source. Use the search links to check official sources before relying on this information.
6.PMID: 39474646 (2024) — Effectiveness and Safety of Hair Growth Formulation Containing Tectona grandis L.f (Teak) Leaf Extract: A Randomized, Double-Blind, Placebo-Controlled Study on Males with Androgenic Alopecia. · Journal of evidence-based integrative medicine
7.PMID: 14459786 (1962) — Contact eczema caused by true teak (Tectona grandis). An epidemiological investigation in a furniture factory. · British journal of industrial medicine
8.PMID: 40733162 (2025) — Geographic Influence and Metabolomics-Driven Discovery of 5-Alpha Reductase Inhibitors in Tectona grandis L.f. (Teak) Leaves. · Molecules (Basel, Switzerland)
9.PMID: 36978912 (2023) — Antioxidant, Anti-Inflammatory and Anti-Diabetic Activities of Tectona grandis Methanolic Extracts, Fractions, and Isolated Compounds. · Antioxidants (Basel, Switzerland)
10.PMID: 35566245 (2022) — Isolation and HPLC Quantitative Determination of 5α-Reductase Inhibitors from Tectona grandis L.f. Leaf Extract. · Molecules (Basel, Switzerland)
11.PMID: 38151632 (2024) — Compound isolation through bioassay-guided fractionation of Tectona grandis leaf extract against Vibrio pathogens in shrimp. · International microbiology : the official journal of the Spanish Society for Microbiology
12.PMID: 36323840 (2022) — Chemical composition of heartwood and sapwood of Tectona grandis characterized by CG/MS-PY. · Scientific reports
13.PMID: 29800113 (2018) — Draft genome of a high value tropical timber tree, Teak (Tectona grandis L. f): insights into SSR diversity, phylogeny and conservation. · DNA research : an international journal for rapid publication of reports on genes and genomes