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Butea superba

Butea Superba (Red Kwao Krua) is a herb from Thai medicine sometimes thought to be the male equivalent of Pueraria Mirifica, a phytoestrogen known as White Kwao Krua; evidence for Butea Superba for these claims is lacking.

Our evidence-based analysis on butea superba features 21 unique references to scientific papers.

Research analysis led by Kamal Patel .
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Summary of Butea superba

Primary Information, Benefits, Effects, and Important Facts

Butea Superba is a tuber vegetable that looks visibly similar to Pueraria Mirifica yet appears to be opposite in effect. This tuber has traditionally been used for the enhancement of male vitality and as an aphrodisiac in Thailand, and appears to be a source of androgenic compounds.

When studies investigated the androgenic effects, there appears to be the classical signs of direct androgenic activation (particularly, an increase in liver enzymes in some studies and growth of male sex organs; a decrease in testosterone levels in serum has been noted possibly due to negative feedback) but unlike its sister herb (Pueraria Mirifica) the bioactives mediating these androgenic effects are not currently known nor are their potencies relative to testosterone known.

Low doses of Butea Superba appear to be safe for human consumption, based on limited evidence, although higher doses have been connected to mutagenicity in mice (300-1000mg/kg, a human equivalent of 48mg/kg or above) and as such are not advisable.

Both studies on Butea Superba and its erectogenic effects appear to have their flaws, so although this herb could potentially be an erectogenic aid it is currently not proven to do so.

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Things To Know & Note

Other Functions:

Primary Function:

Also Known As

Red Kwao Krua

Do Not Confuse With

White Kwao Krua (Pueraria Mirifica), Butea monosperma

  • Possibly Androgenic, and thus would carry many similar risks as higher testosterone levels

How to Take Butea superba

Recommended dosage, active amounts, other details

There is not enough information to recommend supplementation of butea superba, but it appears to be traditionally used in the range of 100-250mg. The exact bioactives that underlie its effects are not known

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Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects butea superba has on your body, and how strong these effects are.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-c - Very High See 2 studies
Currently assumed to be ineffective for erections or erectile dysfunction due to the poor quality of the evidence in existence.

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Research Breakdown on Butea superba

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Butea Superba is one of three herbs with the designation of 'Kwao Krua' in traditional Thai medicine, and is more specifically called 'Red Kwao Krua' with the other relevant herbs being 'White' Kwao Krua (Pueraria Mirifica) and 'Black' Kwao Krua (Mucuna collettii); Butea Superba is visually similar to Pueraria Mirifica.[1]

Butea Superba is a tuber vegetable that has been used for male vitality purposes in Thailand
  • Butesuperin A and B[2]

  • Medicarpin,[3] also found in Butea monosperma

  • Formononetin and Prunetin (isoflavones)[3]

  • 3,7,3'Trihydroxy-4'-methoxyflavone and its glycoside[4]

  • 3,5,7,3',4'-pentahydroxy-8-methoxy-flavonol and its glycoside[5]

  • Soy isoflavones Daidzein and Genistein, as well as Coumestrol[2]

  • Procyanidin B2 and B5, as well as the constituent (-)-epicatechin[6]

A few components are known, but the active component is not currently known

3,7,3'Trihydroxy-4'-methoxyflavone appears to be a cAMP phosphodiesterase inhibitor with an IC50 of 190ug/mL (and its glycoside having an IC50 value of 58ug/mL) which exceed those of the active controls theophylline (615ug/mL) and caffeine (420ug/mL).[7]

In a screening study of Thai herbs, Butea Superba at 0.1mg/mL was able to inhibit acetylcholineasterase in the range of 50-65%, underperforming relative to Tabernaemontana divaricata and Stephania suberosa; all herbs underperformed relative to Galantamine as active control.[8]

May inhibit acetylcholinesterase (and increase acetylcholine as a response) although it underperformed relative to other herbs as well as the active control of Galantamine

Butea Superba has been noted to enhance penile erection in rats at a concentration of 0.1-1000mg/mL (in vitro testing on rat penile tissue) where the mean cavernosal pressure increased at 0.1mg/mL (1.7%), 1mg/mL (6.8%), 10mg/mL (4.2%) and 1000mg/mL (8.3%); somewhat following concentration-dependence.[9] When measuring intracavernosal pressure (ICP), a concentration correlating to 1mg/kg was seen as most effective, and the relaxation effect of Butea Superba appeared to be potentiated when incubated with cGMP (a small signalling molecule that is the result of PDE5 inhibition).[9] This penile erection property has been replicated in diabetic rats (diabetes tends to hinder erectile function secondary to poor blood circulation) with 10mg/kg of the ethanolic extract being the most effective dose (relative to 1mg/kg and 100mg/kg, although all were better than control)[10] and although one study has once reported a potency greater than Viagra, it itself failed to replicate these effects.[11]

Butea Superba ethanolic stem extract at 50mcg/mL in vitro was shown to inhibit ROCK-II by 51.83%, with the successive aqueous extract inhibiting 34.85%;[12] this outperformed herbs such as Sphaeranthus Indicus (22.4% and 36.77%, respectively), Chlorophytum Borivilianum (4.11% and 40.54%) and Tribulus Terrestris (20.48% and 10.83%) but greatly underperformed relative to Syzygium Cumini (87.27% and 89.67%) and Terminalia chebula (87.55% and 86.83%).[12]

Has mechanisms to induce penile relaxation

One study in persons with erectile dysfunction using the basic tuber extract at 500mg for a period of 3 months noted that there were improvements in sexual function as reported by IIEF-5 with 82.4% of patients (n=17 overall) reporting either fair or excellent improvement from baseline.[13] This study is highly limited, if not downgraded in importance from double-blind to pilot, as the entire placebo condition dropped out.[13]

In an open-label trial for persons taking 100mg of Butea Superba noted that the proerectile effects of the herb, when taken 1-2 hours before sex, was comparable to the active control of Viagra; when the study was conducted in a double-blind manner using a different batch of Butea Superba, these effects failed to be replicated.[11] The authors noted a higher degree of variation between batches, and stated that blending of PDE5 inhibitors in the first batch caused a false positive.[11]

Preliminary evidence to support the usage of Butea Superba for the use of erectile dysfunction, but literally the entire placebo group dropped out of the first study and the second appears to have faulty product used (with much less remarkable results coming from the later batch)

When male rats are fed Butea Superba daily for 8 weeks (2mg/kg, 25mg/kg, 250mg/kg, and 1250mg/kg) noted that sperm count was increased approximately 16% at all doses with no dose-dependence noted, and although there appeared to be a trend to increase teste weight only the 1250mg/kg group reached significance.[14]

One study hypothesized that Butea Superba has direct androgenic effects, as evidenced by 150-200mg/kg of the root powder causing a dose-dependent decrease in serum testosterone paired with side-effects commonly associated with androgenicity (increased serum ALP and AST; increased spleen weight).[15] These androgenic effects were replicated in female mice.[16]

Limited evidence in support of it, but there is some evidence to suggest that components of Butea Superba have direct androgenic actions

In rats, Butea Superba at oral doses of 10, 50, or 250mg/kg daily for 8 weeks failed to influence circulating testosterone levels[17] although another study noted a dose-dependent decrease above 250mg/kg.[15] When tested in humans, in a sample of persons with erectile dysfunction an increase from 2.751.40ng/mg to 3.061.37ng/mg (11.2%) was observed but deemed to be not statistically significant.[13] 

At least one case study has noted a case of hyperandrogenemia associated with Butea Superba supplementation, where a 35 year old man took Butea Superba (unreported dosage) for 'a few weeks' for the purposes of hair regrowth and upon clinical examination his serum DHT was 1512pg/mL (152% of the maximum possible value in the normal range), 328ug/mL DHEAS, 1.7% free testosterone and 43.24pg/mL SHBG.[18] Upon cessation of the herb, DHT and sexual desire normalized at 1 week followup.

Highly unreliable effects on circulating testosterone, with decreases (thought to be secondary to androgenic phytonutrients) and increases (reason unknown) both being reported

One study noted that there are some weak phytoestrogens (one pterocarpan and isoflavones) contained in Butea Superba with a relative potency (relative to 17β-estradiol) ranging from 5.27-15.5%.[19] Other components (currently unknown) in the extracts of Butea Superba appear to have anti-estrogenic effects against 17β-estradiol when coincubated.[19]

Potential estrogenic and antiestrogenic effects depending on cellular context, practical significance not known

In male rats either sexually intact or without testicles (orchidectomized) it was noted that 50 and 250mg/kg (not 10mg/kg) was able to suppress the increase in Luteinizing Hormone (LH) associated with removal of the testicles; there was no significant effect in intact rats.[17]

Oral intakes of 1250mg/kg of the tuber to rats for 8 weeks has failed to exert toxic effects,[14] despite this same study making note of a publication (original paper cannot be located) where 360mg/kg injections were lethal via cardiac failure.[14] The Thailand equivalent of the FDA appears to have set the safe limit of this food product at 100mg daily, or 0.2mg per 100g bodyweight (100mg for a 50kg/110lb person).[14]

It has been noted that consumption of high doses of Butea Superba (300mg/kg in rats; human dose of 48mg/kg) may exert genotoxic effects despite lower doses being free from toxicity.[20] This has been noted elsewhere with 1000mg/kg but not 200mg/kg.[21]

Limited evidence all around, but it appears to be safe at low doses (those that seem to be used in nutritional supplementation) although it appears to be mutagenic (causing mutations) at higher doses


  1. ^ Wiriyakarun S, et al. Discrimination of the Thai rejuvenating herbs Pueraria candollei (White Kwao Khruea), Butea superba (Red Kwao Khruea), and Mucuna collettii (Black Kwao Khruea) using PCR-RFLP. J Nat Med. (2012)
  2. ^ a b Isolation of new isoflavonolignans, Butesuperins A and B, from a Thai miracle herb.
  3. ^ a b Ngamrojanavanich N, et al. Cytotoxic constituents from Butea superba Roxb. J Ethnopharmacol. (2007)
  4. ^ Flavonoid and Flavonoid glycoside from Butea superba Roxb. and their cAMP Phosphodiesterase Inhibitory Activity.
  5. ^ Yadava RN, Reddy KI. A new bio-active flavonol glycoside from the stems of Butea superba Roxb. J Asian Nat Prod Res. (1998)
  6. ^ Nuengchamnong N, et al. HPLC coupled on-line to ESI-MS and a DPPH-based assay for the rapid identification of anti-oxidants in Butea superba. Phytochem Anal. (2005)
  7. ^ Flavonoid and Flavonoid glycoside from Butea superba Roxb. and their cAMP Phosphodiesterase Inhibitory Activity.
  8. ^ Ingkaninan K, et al. Screening for acetylcholinesterase inhibitory activity in plants used in Thai traditional rejuvenating and neurotonic remedies. J Ethnopharmacol. (2003)
  9. ^ a b Tocharus C, Smitasiri Y, Jeenapongsa R. Butea superba Roxb. enhances penile erection in rats. Phytother Res. (2006)
  10. ^ Tocharus C, et al. Butea superba (Roxb.) improves penile erection in diabetic rats. Andrologia. (2012)
  11. ^ a b c Cortés-González JR, et al. The use of Butea superba (Roxb.) compared to sildenafil for treating erectile dysfunction. BJU Int. (2010)
  12. ^ a b Goswami SK, et al. Screening for Rho-kinase 2 inhibitory potential of Indian medicinal plants used in management of erectile dysfunction. J Ethnopharmacol. (2012)
  13. ^ a b c Cherdshewasart W, Nimsakul N. Clinical trial of Butea superba, an alternative herbal treatment for erectile dysfunction. Asian J Androl. (2003)
  14. ^ a b c d Manosroi A, et al. Effects of Butea superba on reproductive systems of rats. Fitoterapia. (2006)
  15. ^ a b Cherdshewasart W, et al. Androgen disruption and toxicity tests of Butea superba Roxb., a traditional herb used for treatment of erectile dysfunction, in male rats. Maturitas. (2008)
  16. ^ Malaivijitnond S, et al. Androgenic activity of the Thai traditional male potency herb, Butea superba Roxb., in female rats. J Ethnopharmacol. (2009)
  17. ^ a b Malaivijitnond S, et al. Luteinizing hormone reduction by the male potency herb, Butea superba Roxb. Braz J Med Biol Res. (2010)
  18. ^ Chaiyasit K, Wiwnaitkit V. Hyperandrogenemia due to ingestion of Butea superba. Indian J Endocrinol Metab. (2012)
  19. ^ a b Cherdshewasart W, Mahapanichkul T, Boonchird C. Estrogenic and anti-estrogenic activities of the Thai traditional herb, Butea superba Roxb. Biosci Biotechnol Biochem. (2010)
  20. ^ Cherdshewasart W, et al. Mutagenic and antimutagenic effects of the traditional herb used for treating erectile dysfunction, Butea superba Roxb. Biosci Biotechnol Biochem. (2010)
  21. ^ Pongpanparadon A, Aritajat S, Saenphet K. The toxicology of Butea superba, Roxb. Southeast Asian J Trop Med Public Health. (2002)