Does CBD Affect Hormones (and is it good or bad)?

This is the most frequently asked question I’ve been hit with lately, and I think its a really juicy one because it highlights the potency that CBD can act within the body.

Q. Does CBD affect hormones?

Hormones are special types of chemical messenger that enable one part of the body to ‘talk’ to another, so the body is constantly operating in synchronous harmony.

Collectively, the hormones and the glands they are released from are known as the endocrine system.

Glands are found throughout the body. Certain glands release specific hormones into the bloodstream so that they can travel to other organs and glands to control their function. This forms a communication network which is giving and receiving constant feedback to maintain optimal bodily function.

Some of the major roles of hormones are:

• Fertility
• Sex drive
• Appetite
• Metabolism
• Mood
• Energy

Levels of hormones naturally fluctuate depending on whether it’s day or night, and what stage of life a person has reached, eg adolescence, pregnancy or menopause.

Hormones can also become imbalanced throughout any stage of life. These imbalances can be part of the driving force behind chronic illnesses. One of the major challenges we face today is the impact of environmental toxicity on our hormones - plastics, industrial chemicals and pesticides all mess with the endocrine system.

Aside from reducing our exposure to toxicity, we can look for ways to support healthy hormones through the foods, herbs and exercise we engage with.

Major Hormones

• Thyroid Hormones
• Testosterone
• Estrogen
• Growth Hormone
• Insulin
• Cortisol

How does CBD affect hormones?

There are three main ways that CBD can change how hormones work in the body.

Synthesis

Cannabinoid receptors are found on major glands throughout the body. When these receptors are activated by our bodies endocannabinoids, this can alter the secretion of hormones, and change their impact on target organs.

Since CBD can also (indirectly) interact with cannabinoid receptors, it has the power to alter the synthesis and secretion of hormones as well. 

Most changes in hormone synthesis and secretion start in the hypothalamus, when cannabinoid receptor 1 is activated. This starts a series of hormonal messages that trickle down to other glands, which then secrete their own hormones in response.

Source

Cannabinoid receptor 1 is also found on most other glands and organs, so can control hormonal balance directly as well.

Response

Cannabinoids like CBD can influence the ‘volume’ of message received at a target organ from a hormone. The sensitivity of a cell receptor for a certain hormone can either be increased or decreased by cannabinoids - increasing or decreasing the volume / strength of the message.

Breakdown

Hormones need to be cleared and disposed of after they have done their jobs, so continual balance can be maintained in the body. Cannabinoids like CBD can alter the speed of enzymes that break hormones down.

Thyroid Hormones

Although there’s no studies looking directly at CBD on thyroid hormones, there have been some which have looked at the effect of endocannabinoids on them.

Since CBD affects endocannabinoids, we can only speculate as to the effects.

Thyroid hormones TSH, T4 and T3 are all designed to rev up cellular metabolism, helping us mobilise energy to use it.

Endocannabinoids on the other hand encourage the sparing and storage of energy, in part by reducing thyroid hormones (1).

Blocking endocannabinoids increases TSH, T4 and T3, which may help raise thyroid function (2).

The effect of CBD could theoretically go both ways, since it can both dampen and stimulate endocannabinoids. Whether CBD may increase or decrease thyroid hormones might depend on someone being hypothyroid, hyperthyroid or having a normal thyroid.

Anandamide was found to suppress TSH only in hypothyroid and normal thyroid conditions (high TSH), and not in hyperthyroid conditions (low TSH) (2).

This is potential evidence of an adaptogenic effect of (endo)cannabinoids, helping to balance individuals to their own needs. CBD may help endocannabinoids support individual balance. 

Testosterone

Testosterone is an important hormone involved mainly in reproduction and sex drive, but also has other roles in regulating mood and energy.

Its mainly synthesised in the testes and ovaries, and is made in repose to hormonal signals from the hypothalamus (LH and FSH).

CBD has been shown to effect LH and FSH levels in monkeys, albeit at doses much higher than we would realistically use. After 90 days, LH and FSH were increased, but no changes were seen in testosterone, except a decrease at the highest dose (3).

In rats and mice, higher doses (higher than most of us would take) reduced testosterone after 10 - 34 days (4).

CBD has been suggested to reduce testosterone production by inhibiting the enzyme 17α‐hydroxylase, which makes Testosterone in leydig cells of the testes (4).

However, CBD also inhibits specific cytochrome p450 enzymes in the liver which break testosterone down (4).

So theoretically, reducing the breakdown of testosterone may offset reductions in synthesis. But thats just speculation at this point. Also, these studies show a decrease in testosterone at high doses used mid term. 

We need to see trials in humans before we can say anything concrete. But for men who want to take a cautious approach:

• Use moderate doses (5 - 100mg/day)
• Cyclical use: take a break every few months to washout accumulated CBD - sweating through sauna and exercise.
• Exercise regularly to promote natural testosterone production whilst using CBD.

Estradiol E2 (Estrogen)

Estrogen levels are important because they influence sexual development, fertility, and susceptibility to female diseases such as breast cancer.

Estrogen is made in the ovaries, in repose to hormones LH and FSH released from the pituitary gland. Its levels in the body are also controlled by enzymes that make it and break it down.

Studies using CBD in cells found that it suppresses estrogen production directly, by inhibiting an enzyme that makes it from testosterone, called aromatase (5).

Aromatase inhibitors are used to reduce estrogen levels in cases of breast cancer and post menopause (6). 

CBD also encourages the breakdown of estrogen by speeding up cytochrome p450 enzymes that break it down (7).

Theoretically, this points to an anti-estrogenic effect of CBD, lowering levels of estrogen. But this has not been shown in animal or human research so far.

Moderate to high doses of CBD were not associated with changes in LH, FSH and estrogen after 90 days in female monkeys (3).

More research is needed before any conclusions can be made on how CBD affects estrogen.

Growth Hormone

Growth hormone (GH), as the name suggests, signals for the reproduction and regeneration of cells, stimulating growth and development in the body.

A few benefits of increased growth hormone output are:

• Strong bones
• Increased muscle mass
• More energy
• Enhanced ability to burn fat
• Improved exercise capacity

A single dose of CBD had no effect on Growth Hormone levels in 11 healthy volunteers (8).

However other cannabinoids like THC, especially when used long term have been shown to reduce GH. THC reduced GH secretion from the pituitary gland via cannabinoid receptor 1 (9), and reduced circulating GH levels in adults (10).

Since CBD also interacts with CB1, long term use could affect GH levels. We need more studies to assess whether there’s a positive or negative effect of CBD on GH levels.

Insulin

Insulin is a major hormone involved in the use and storage of energy. It has a great impact on body weight and energy levels, via regulating metabolism.

We need insulin to tell our cells when to take in sugar from the bloodstream. Healthy insulin levels mean we use sugar effectively in our muscles and liver, and don’t store too much in fat tissue.

Too much insulin is a driving force of weight gain and diabetes, and its often raised in repose to high sugar consumption.

In diabetic rats, CBD has been shown to reduce excessively high levels of insulin, whilst maintaining blood sugar levels (11). This means CBD may help sensitise muscles and liver cells to take up sugar more efficiently, helping to maintain stable blood sugar.

CBD also reduces body weight gain in rats (12). By reducing insulin, CBD may discourage fat cells from storing excessive sugar, which could reduce weight gain.

Unfortunately the only study in humans looking at insulin levels with CBD used a low dose, which did not affect insulin levels in the diabetic patients. However, CBD did increase the levels of another hormone gastric inhibitory polypeptide (GIP) which controls the release on insulin, hinting at a possible effect on insulin with higher doses (13).

Cortisol

Cortisol's major role is as a stress hormone, and tells the rest of body that a stressful event is happening. Its produced in the adrenals, in response to sensory inputs to the hypothalamus from our experience of the world around us.

Short term spikes in cortisol are beneficial, as they allow us to be aware of potentially dangerous things in our environment that threaten our survival.

Unfortunately staying on top of bills, work and relationships can also be perceived as a threat to survival, and lead to chronic cortisol output and unresolved stress.

CBD is quite incredible at resolving stress, though. It essentially acts as a breaking system on the stress response, by acting (indirectly) through cannabinoid receptors in the hypothalamus. Effectively, CBD tells the adrenals to chill out on cortisol production.

Human and studies have shown CBD can modulate cortisol output (7), (14), (15), and its one of the major reasons why so many people may find it soothing.

CBD and HRT

We're still in the early days of research with CBD in general, even less so when it comes to its impact on hormonal regulation. Currently we are reduced to speculating based on the mechanisms of action from animal studies, without much idea of real world effects in humans.

CBD may be able to help 'normalise' bodily systems to a certain extent, including some degree of hormonal balance. But this may depend on the severity of the underlying imbalance in the first place, which in more severe cases CBD is unlikely to have a meaningful effect.

The reason for this relates to the fact that CBD does not have a powerful stimulatory effect on hormonal production, but more so in maintaining the balance between various different hormones. In light of this, CBD would not be a viable alternative to HRT, but may be complimentary to helping regulate the balance of hormones that are given in a supplementary way.

Its unclear what the benefits of HRT and CBD would be combined, and may be different between individuals. Its often the case that combining different therapies has a complementary and synergistic effect. If you are interested, its worth discussing this first with your Doctor or Endocrinologist.

Summary

Although there are (initial) changes in hormone levels with CBD, other studies suggest a tolerance can be developed to cannabinoids (16). Initial hormone changes may correct overtime, or are compensated for by other mechanisms (ie hormone receptor sensitivity). So basically, its too early to say with much certainty just how CBD affects hormones long term and what that translates to health wise. 

Effects of CBD on hormones:

• Insulin - likely positive 
• Cortisol - likely positive
• Thyroid - too soon to say although likely positive
• Testosterone - likely negative if used at high doses for a long time without exercise
• Growth Hormone - too soon to say
• Estrogen - too soon to say