My guest is Dr. Nirao Shah, MD, PhD, a professor of psychiatry, behavioral sciences and neurobiology at Stanford University School of Medicine. We discuss how the brains of males and females differ and how those differences arise from different genes and hormones during fetal development, in childhood and adulthood. We discuss what drives male- versus female-specific behaviors and how hormonal fluctuations across the lifespan, including puberty, the menstrual cycle, menopause and aging – affect behavior, cognition and health. Additionally, we discuss how biology relates to gender identity and the impact of hormone therapies on brain circuits that regulate mating, parenting and social bonding. Episode show notes: https://go.hubermanlab.com/rJuyFMY *Thank you to our sponsors* AG1: https://drinkag1.com/huberman Maui Nui: https://mauinuivenison.com/huberman Eight Sleep: https://eightsleep.com/huberman LMNT: https://drinklmnt.com/huberman Function: https://functionhealth.com/huberman *Follow Huberman Lab* Instagram: https://www.instagram.com/hubermanlab Threads: https://www.threads.net/@hubermanlab X: https://twitter.com/hubermanlab Facebook: https://www.facebook.com/hubermanlab TikTok: https://www.tiktok.com/@hubermanlab LinkedIn: https://www.linkedin.com/in/andrew-huberman Website: https://www.hubermanlab.com Newsletter: https://www.hubermanlab.com/newsletter *Dr. Nirao Shah* Stanford lab website: https://med.stanford.edu/nirao.html Stanford academic profile: https://med.stanford.edu/profiles/nirao-shah Publications: https://med.stanford.edu/profiles/nirao-shah#publications X: https://x.com/shah_laboratory *Timestamps* 00:00:00 Nirao Shah 00:02:11 Mice, Humans & Brain, Biological Conservation 00:05:25 Hormones, Nature vs Nurture 00:07:13 Biological Sex Differences, Chromosomes & SRY Gene, Hormones 00:16:01 Sponsors: Maui Nui & Eight Sleep 00:19:09 Androgen Mutations, Feminization & Masculinization 00:22:04 SRY Gene; Animals & Sexual Trans-Differentiation 00:27:49 Hormones & Biological Brain Differentiation 00:31:22 Congenital Adrenal Hyperplasia, Androstenedione; Stress & Pregnancy 00:35:56 Genes, Brain Differentiation & Sexual Identity; Congenital Adrenal Hyperplasia 00:43:37 Testosterone, Estrogen & Brain Circuits 00:47:27 Sponsors: AG1 & LMNT 00:50:36 Intersex Individuals, Castration 00:52:23 Female Sexual Behavior, Brain, Testosterone & Pheromones 00:57:58 Identify as Heterosexual or Homosexual, Difference in Hormone Levels? 01:00:42 Gender, Sexual Orientation & Hormones; Hormone Replacement Therapy 01:10:21 Aromatization; Steroid Hormones & Gene Expression 01:15:00 Kids & Changing Gender Identity 01:19:05 Sexual Behavior, Refractory Period & Male Brain, Tacr1 Cells 01:21:31 Sponsor: Function 01:23:19 Hypothalamus, Dopamine, Prolactin, Cabergoline, Libido, Dopamine 01:27:05 Brain Circuits, Aggression & Sexual Behavior 01:32:40 Refractory Period; Age, Testosterone & Libido 01:36:07 Tacr1 Cells in Females, Periaqueductal Gray & Innate Behaviors 01:40:00 Parenting Behaviors & Brain Circuits; Pet Dogs 01:43:12 Oxytocin, Pair Bonding, Vasopressin; Biological Redundancy 01:47:22 Libido, Melanocortin, Tacr1 Neurons; GLP-1 Agonists, Clinical Trials; Kisspeptin 01:56:43 Female Brain Changes, Menstrual Cycle, Pregnancy, Menopause; Estrogen; Men & Hormone Fluctuation? 02:04:10 Life Experience Male vs Female, Sex Recognition, Behaviors & Context 02:16:05 Pain Management; Endocrine Disrupters, Gender Identity 02:21:03 Future Projects 02:24:29 Zero-Cost Support, YouTube, Spotify & Apple Follow & Reviews, Sponsors, YouTube Feedback, Protocols Book, Social Media, Neural Network Newsletter Disclaimer & Disclosures: https://www.hubermanlab.com/disclaimer