Weed and Testosterone: What Cannabis Really Does to Your Hormones

How Cannabis Talks to Your Hormones

The endocannabinoid system, the one THC hijacks, runs all through your body. That includes the chain that controls testosterone: the hypothalamus in your brain, the pituitary gland just below it, and the testes.

Doctors call this chain the HPG axis. The pituitary sends a signal called luteinizing hormone (LH), and that signal tells the testes to make testosterone.

All three parts of the chain have cannabinoid receptors. So in theory, THC can interfere with every step, from the brain’s first signal to the sperm cells themselves (Lim et al. 2023). Whether that actually lowers testosterone in real men is a different question.

What the Research Actually Shows

The evidence on cannabis and testosterone is genuinely mixed. Headlines say weed tanks your testosterone. The bigger studies mostly don’t back that up.

A large Danish study of 1,215 young men found that men who smoked weed more than once a week had about 28 percent lower sperm counts. But their testosterone was slightly higher than in non-users, not lower (Gundersen et al. 2015, American Journal of Epidemiology).

A US study of 1,577 men found no difference in testosterone between men who had ever used weed and men who never had. Men who had used more recently actually had slightly higher levels (Thistle et al. 2017).

When researchers pooled nine studies with nearly 4,800 men, they found no clear difference in testosterone between users and non-users. They also say the studies are too small and too different from each other to rule out an effect (Belladelli et al. 2021).

What the bigger studies found

Study	Who	What they found
Denmark, 2015	1,215 young men	About 28 percent lower sperm count with use more than once a week. Testosterone slightly higher.
USA, 2017	1,577 men	No difference between ever users and never users. Slightly higher with recent use.
Pooled analysis, 2021	9 studies, nearly 4,800 men with hormone data	No clear difference in testosterone. Too little good data to rule out an effect.

So where does the “weed lowers testosterone” idea come from? Partly from a well-known study from 1974 that reported lower testosterone after intensive, long-term use, and partly from the fact that THC clearly acts on the hormone chain. NIDA, the US research institute on drugs, keeps an overview of what is known about cannabis and health.

The honest summary: heavy use may affect your hormones, but low testosterone is not a proven, typical result of smoking weed. If you feel like your testosterone is low, a blood test tells you more than any study can. Women face their own hormonal layer, which one teacher describes in quitting weed as a woman.

Where the Signal Is Clearer: Sperm

The hormone numbers are mixed. The sperm numbers point more in one direction. In the Danish study, regular users had lower sperm counts. Men who combined weed with other drugs had about half the sperm count of non-users.

Reviews of the research also link cannabis use to lower sperm motility and more abnormally shaped sperm (Lim et al. 2023). If you’re trying to have a child, this is the part that matters most.

Sperm take time to grow. In humans, the whole process from start to finished sperm takes about 74 days. So any change after quitting shows up on that kind of timescale, not within a week.

Symptoms That May Be Related to Hormonal Changes

Many long-term users notice things that look a lot like low testosterone: less drive and energy, a harder time building muscle, a lower sex drive, a flat mood.

But these overlap heavily with depression and with what weed does to your dopamine system. That makes it hard to tell what’s hormones and what’s something else.

Then there’s sleep. Most of a man’s daily testosterone is released during sleep. In one study, healthy young men who slept only five hours a night for a week had 10 to 15 percent lower daytime testosterone (Leproult and Van Cauter 2011).

Heavy use messes with how you sleep, and withdrawal makes sleep rough for a while too. That’s an indirect route from weed to your hormones, separate from anything THC does to the hormone chain directly.

What Happens to Testosterone After Quitting

Honestly, there are very few studies that followed men’s hormones after they quit. So nobody can promise you a testosterone boost from quitting.

What does change is everything around it. In our Cannabis Detox Program, the first weeks after quitting are split into three phases:

What changes after your last joint

1. Release: day 1 to about day 5The most physical part. Sleep is at its worst, with vivid dreams and waking at night.
2. Resilience: day 5 to about week 3 or 4The body calms down. Sleep slowly gets better, though it can stay patchy for a few more weeks.
3. Clarity: until about week 7Sleep, energy, drive and mood slowly come back. Most daily users sleep clearly better by now.
4. After thatAbout 74 days after quitting, a full new round of sperm has formed without THC.

None of this is a hormone test. But sleep, energy and drive are exactly the things that low testosterone and heavy weed use both drag down.

Men who quit and also start exercising, sleeping enough, and eating well give their body the best conditions to make testosterone. The benefits of quitting weed include improvements in exactly those things: sleep, energy and motivation.

How long that takes depends on how long you’ve been using, your age and where you started. If low energy, low drive or changes in your body have been part of your life with weed, quitting removes one thing that may have been working against you. If you want a structured way through it, our Cannabis Detox Program takes you through all three phases, from the rough first days to feeling clear again.