L-Carnitin

L-carnitine helps transport fatty acids into mitochondria for energy production and has been discussed in connection with fertility, mood, and nerve health. 1

• Fertility: It may support egg and sperm quality, including sperm motility; one fertility specialist described using it with vitamin C and CoQ10 for male patients with abnormal sperm parameters. Huberman also noted positive effects reported for women with PCOS. 2 3
• Fatty-acid transport and androgen receptors: Carnitine helps carry fatty acids across the mitochondrial membrane so they can be used for energy. The guest also said it may increase androgen-receptor density, potentially locally when injected into a muscle. 4
• Mood and nerve health: Early research discussed in the episode suggests L-carnitine may ease depressive symptoms. Acetyl-L-carnitine was also described as potentially reducing chronic pain and supporting peripheral nerve health, including in diabetic neuropathy. 5 6
• Oral versus injectable: Oral L-carnitine was described as having low bioavailability—about 10% in one discussion—whereas injection was described as 100% bioavailable. Injectable use can burn or hurt, especially if given subcutaneously; the guest discussed intramuscular administration and medical supervision. 7 8 9