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How Hormones Shape Sexual Development | Huberman Lab Essentials — Whalespan

Content›Video›How Hormones Shape Sexual De…

How Hormones Shape Sexual Development | Huberman Lab Essentials

Andrew Huberman39m · 2025-02-13

Claims Made

57

Claims Supported

46

Support Rate

81%

Support rate

46 of 57 claims supported

46 supported11 partial / not

Claims from this content

45

✓Well SupportedDHT causes facial hair growth and scalp hair loss due to genetically determined differences in receptor sensitivity and density.✓Well SupportedChronic marijuana use (more than twice a week) significantly reduces testosterone and elevates aromatase enzymes.✓Well SupportedIndividuals with XY chromosomes and a mutated androgen receptor gene will develop as infertile females despite having the SRY gene and producing testosterone.✓Well SupportedIndividuals with a deficiency in 5-alpha reductase can appear feminized early in life and then masculinize at puberty, developing a penis.Well Supported

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A. Volkovreader

4h

Bookmarking — the dossier-vs-overview split is the right call. Most of the time I want overview; sometimes I want receipts.

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✓

Dihydrotestosterone (DHT) is the dominant androgen in males, responsible for aggression, muscular strength, beard growth, and male pattern baldness.

✓Well SupportedHuman sperm counts declined significantly between 1940 and 1990, from 113 million/mL to 66 million/mL.

✓Well SupportedStudies suggest defects in testicular and/or ovarian development from exposure to cell phone emitted waves.

✓Well SupportedDuring puberty, kisspeptin stimulates GnRH and LH release, leading to testosterone production and secondary sexual characteristics.

✓Well SupportedAnecdotal observations suggest cannabis smokers have a higher incidence of gynecomastia.

✓Well SupportedThe conversion of testosterone to dihydrotestosterone (DHT) primarily occurs in hair follicles and prostatic tissue, mediated by the enzyme five-alpha reductase.

✓Well SupportedDihydrotestosterone is responsible for the primary growth of the penis, while testosterone is involved in secondary sexual characteristics.

✓Well SupportedAdequate dihydrotestosterone (DHT) production is necessary for full physical maturation during adolescence.

✓Well SupportedThe masculinization of the brain is accomplished by estrogen, not testosterone, although testosterone can be converted to estrogen by the enzyme aromatase.

✓Well SupportedHormones affect the body, brain, and periphery with acute and long-term effects, including on gene expression.

✓Well SupportedSteroid hormones like testosterone and estrogen can alter gene expression and influence traits such as muscle growth.

◐Partially SupportedHerbicides can negatively impact sexual development at the gonadal and brain levels by disrupting hormones like testosterone and estrogen.

◐Partially SupportedAlcohol consumption can increase estrogenic activity, potentially impacting pubertal development.

◐Partially SupportedSteroid hormones like testosterone and estrogen can have immediate effects and also change gene expression.

◐Partially SupportedAndrostenedione is produced at high levels in female hyenas, causing enlargement of their genitalia.

◐Partially SupportedCannabis promotes circulating estrogen in the body, potentially counteracting masculinizing effects of testosterone and dihydrotestosterone.

◐Partially SupportedThe Y chromosome contains genes that suppress the formation of Müllerian ducts.

◐Partially SupportedMasculinization and feminization involve demasculinizing and defeminizing the body and brain as normal biological functions.

◐Partially SupportedAndrostenedione is a prohormone to testosterone, converted by the enzyme 17-beta-hydroxy steroid dehydrogenase.

◐Partially SupportedHormones impact tissue growth and development within an individual, between mother and offspring, and mediate communication between plants and animals.

◐Partially SupportedSmoking marijuana during pregnancy can shift fetal hormone patterns towards more estrogenic outcomes.

◐Partially SupportedAtrazine exposure in male frogs is associated with testicular abnormalities, with the most severe malformations affecting the gonad itself.

✕Not SupportedDrinking alcohol during pregnancy can lead to fetal alcohol syndrome, characterized by cognitive deficits and physical malformations.

◐Partially SupportedEnvironmental factors and home products can impact hormone levels and sexual development.

◐Partially SupportedThe marijuana plant possesses estrogenic properties.

◐Partially SupportedHormones released from the brain can trigger the release of other hormones in the body.

◐Partially SupportedThe ratio of normal sperm morphology decreased from 56.4% to 26.9% between 1981 and 1991.

◐Partially SupportedHerbicides can disrupt estrogens, potentially explaining earlier puberty in young girls.

◐Partially SupportedFor a hormone to have effects, it must be present, bind to its receptor, and act on target cells.

◐Partially SupportedHormonal sex, influenced by estrogen and testosterone, affects morphological sex, determining physical characteristics.

◐Partially SupportedThere is no evidence in quality peer-reviewed studies showing that cell phones are harmful to the brain or that holding a phone to the ear or using Bluetooth is detrimental.

◐Partially SupportedHormones are chemical substances released from glands or neurons that travel to affect other organs and tissues in the body.

◐Partially SupportedHair loss drugs that prevent testosterone conversion to DHT can cause side effects associated with low DHT levels.

◐Partially SupportedEnvironmental factors can negatively impact sexual development regardless of chromosomal background.

◐Partially SupportedHormones like cortisol and adrenaline have fast-acting effects, while sex steroid hormones like testosterone and estrogen have slower effects.

◐Partially SupportedAndrostenedione was a major performance-enhancing drug of abuse in Major League Baseball.

◐Partially SupportedHormones from the mother and developing fetus can influence whether the fetal brain is organized as masculine or feminine.

◐Partially SupportedSome plants have evolved the capacity to increase estrogen levels in animals that consume them as a defense mechanism to lower male sperm counts and control animal populations.

◐Partially SupportedSome plants, like pine pollen, produce compounds that are equivalent to testosterone.

◐Partially SupportedHerbicides are a primary cause of reduced sperm counts and can have profound effects on sexual development, impacting gonads and the brain.

◐Partially SupportedThe transition from chromosomal sex to gonadal sex is a critical early developmental fork.