How Hormones Shape Sexual Development | Huberman Lab Essentials

Andrew Huberman

13 feb 2025

Episode description

In this Huberman Lab Essentials episode, I explain the crucial role hormones play in shaping the sexual development of both the brain and body.

I discuss how biological masculinization and feminization depend on factors such as genetics, hormone ratios, and receptor availability. I also explore how hormones like testosterone, estrogen, and other steroid hormones influence sexual characteristics and brain development. Additionally, I examine the impact of environmental factors—such as herbicides like atrazine, cannabis, alcohol, and even cell phones—on hormone function and reproductive health.

Episode show notes: https://go.hubermanlab.com/Do6MuHz

Huberman Lab Essentials are short episodes focused on essential science and protocol takeaways from past full-length Huberman Lab episodes. Watch or listen to the full-length episode: https://youtu.be/J7SrAEacyf8

*Timestamps*
00:00:00 Huberman Lab Essentials; Hormones, Sexual Development
00:01:25 Chromosomal Sex, Gonadal Sex, Hormonal Sex, Morphology
00:06:06 Steroid Hormones, Sexual Characteristics
00:09:10 Primary & Secondary Sexual Characteristics, Dihydrotestosterone (DHT), Kisspeptin
00:13:23 Masculinization of Brain, Estrogen
00:14:41 Herbicides, Atrazine, Hormone Effects, Sperm Counts
00:20:29 Female Sexual Development, Androgen Insensitivity Syndrome
00:24:03 Cannabis & Aromatase Activity, Gynecomastia; Alcohol & Estrogen Activity
00:27:00 Cell Phones & Gonads
00:29:46 Beard & Hair Growth, DHT
00:33:04 Hyenas, Hormones, Androstenedione; Plants
00:38:06 Recap & Key Takeaways

Disclaimer & Disclosures: https://www.hubermanlab.com/disclaimer

Episode description

Mindsip insights from this episode:

Recognize estrogen's role in masculinizing the male brain

It is estrogen, converted from testosterone by the enzyme aromatase, that is responsible for masculinizing the male brain during development, not testosterone itself.

#estrogen

#neurology

Understand DHT's role in male fetal development

It is not testosterone but its derivative, dihydrotestosterone (DHT), that is responsible for the development of the penis in a male fetus.

#DHT

#testosterone

Understand cannabis effects on estrogen levels

Cannabis use promotes the activity of the aromatase enzyme, which converts testosterone into estrogen and can lead to estrogenic effects like gynecomastia in males.

#cannabis

#estrogen

Eliminate atrazine exposure to protect testicular health

The common herbicide atrazine, found in many waterways, has been shown in federally funded studies to cause severe testicular malformations in animals and is linked to declining human sperm counts.

#environment

#testosterone

Limit cell phone exposure to protect gonadal health

A growing body of scientific literature suggests that chronic exposure of the gonads to cell phone-emitted waves could create serious issues for testicular and ovarian health.

#EMF

#fertility

Understand DHT's role in beard growth and baldness

Dihydrotestosterone (DHT) is the primary hormone responsible for both beard growth and male pattern baldness, with the outcome depending on the genetic pattern of DHT receptors on the face versus the scalp.

#DHT

#hair-loss

Beware side effects of hair loss drugs inhibiting DHT conversion

Drugs designed to prevent hair loss work by inhibiting the conversion of testosterone to DHT, which can lead to side effects associated with low DHT, such as reduced libido and strength.

#hair-loss

#side-effects

Utilize plant hormones to control animal populations

Some plants have evolved to produce estrogen-like compounds as a defense mechanism to lower the sperm counts of animals that consume them, thereby controlling their population.