How do opioids affect endocrine health?

Opioids are a complex class of drugs that have varying effects throughout the body, and it’s crucial to understand how they work and affect bodily functions and systems. The endocrine system, which produces hormones, is one area that requires specific attention because it’s responsible for so many functions—and it’s easy to take those functions for granted.

This guide covers the basics of the endocrine system, how it works, and the effects of opioids on the endocrine system so you have a better understanding of what’s going on in your body.

What is the endocrine system?

The human body produces dozens of different hormones. These chemicals help organs communicate with each other and regulate the behavior of the body’s many different systems.

Glands within the body produce and release hormones into the blood, where they travel between organs and deliver important information. Hormones influence just about everything the body does, from digesting and metabolizing food to sleeping and reproducing. They even contribute to our moods and how we experience stress¹.

The system that controls the complex ebb and flow of hormones in the body is known as the endocrine system. It’s made up of several glands located in different parts of the body, each of which creates unique hormones.

What parts of the body make up the endocrine system?

In general, there are nine different types of glands that make up the endocrine system, creating all the hormones necessary to regulate bodily functions. The ovaries, pancreas, parathyroid gland, pineal gland, and testes all produce important compounds, like:

• Melatonin
• Insulin
• Estrogen
• Androgen
• Testosterone

However, the remaining four glands are of higher concern when it comes to the endocrine effects of opioids. These are the adrenal, hypothalamus, pituitary, and thyroid glands¹. 

Adrenal glands

The adrenal glands are located near the kidneys, and their primary function is to produce adrenaline and cortisol. Also known as epinephrine, adrenaline is a key component of the flight-or-fight response, and it increases blood flow and alertness.

Cortisol is a part of the body’s stress response, and it is known to suppress the immune system, increase metabolism, and decrease the production and formation of bone. 

Hypothalamus

The hypothalamus is found in the brain, and it serves as a bridge between the nervous system and endocrine system, allowing the brain and body to communicate more effectively. This gland regulates functions like body temperature, circadian rhythms, and hunger. It also affects feelings of sexual arousal.

Pituitary gland

Right below the hypothalamus lies the pituitary gland. It’s tiny—less than half an inch in diameter—but it controls some of the body’s most important functions. In children, the pituitary gland oversees the production of growth hormones. It also regulates blood pressure, some sexual functions, and pain relief.

Thyroid gland

Located in the neck, the thyroid primarily produces two hormones: triiodothyronine (known as T3) and tetraiodothyronine (known as T4). These two hormones are named after the number of iodine atoms they contain, and they regulate heart rate, appetite, and digestion. They also help maintain healthy cholesterol levels. 

What bodily functions does the endocrine system regulate?

In truth, the endocrine system influences every bodily function imaginable, and the system is incredibly complicated, with many glands having overlapping roles or affecting different aspects of the same bodily function. This means the effects of opioids on the endocrine system can be far-reaching and difficult to predict and study. 

Can opioids cause endocrine dysfunction?

Yes, opioids affect the body’s production of various hormones in both short- and long-term usage scenarios. Opioid use may disrupt many different aspects of the endocrine system, depending on the individual. Luckily, in most cases, these effects are not permanent and can be reversed and treated if properly identified by medical professionals. 

The effects of opioids on the endocrine system

Metabolism + digestion

Across the board, two of the most common side effects of opioid use, whether prescribed or recreational, are constipation and diarrhea. It might seem strange that these two seemingly opposite symptoms are common, but they both stem from issues involving digestion.

These digestive issues may be caused by opioids’ propensity for inhibiting what is known as the hypothalamic-pituitary-adrenal (HPA) axis². This means opioids interfere with the hypothalamus, pituitary gland, and adrenal glands, preventing them from communicating with one another and causing each to produce hormones without input from the others. This can lead to over- or underproduction of hormones crucial in regulating metabolism and digestion, which ultimately results in changes in appetite and how the body processes waste. 

Sex hormones

Many individuals who have used opioids report feeling a change in libido, typically experienced as severely decreased interest in sex. This is the result of opioids’ effect on the hypothalamic-pituitary-gonadal (HPG) axis².

Opioid use lowers the secretion of key hormones in the hypothalamus and pituitary gland while decreasing the production of sex steroids in the ovaries and testes. This condition is known as hypogonadism.

Decreased dopamine secretion from opioid use further worsens the issue, resulting in a much lower sex drive than usual. Extended opioid use is generally linked to sex hormone decreases, though the severity varies by substance.

In addition to affecting sexual arousal and performance, hypogonadism can reduce bone mineral density in both men and women. These effects tend to be more prevalent in men because they have a greater risk of experiencing hypogonadism⁵.

Stress, emotional regulation + cognition

Chronic opioid use is strongly correlated with worsening cognitive function. Some research shows that opioid use reduced working memory, increased risk-taking behaviors, and worsened cognitive flexibility³.

These symptoms may also be correlated with issues of emotional regulation, like mood swings, anxiety, and depression, which are all common side effects of prolonged opioid use. The hormones produced by the thyroid are responsible for many of these functions. Hypothyroidism—which occurs when the thyroid is less active than it should be—is commonly accompanied by brain fog and memory loss, while an overactive thyroid may cause anxiety.

It’s possible that sustained opioid use may increase the amount of T3 and decrease the amount of T4 produced by the thyroid⁴, but the data are not consistent across studies².

Another side effect of opioid interference in the HPA axis is known as opioid-induced adrenal insufficiency (OIAI). With this condition, cortisol production related to stress may be severely inhibited. In stressful social situations, this leads to increased negative emotions and a less generous perception of the self⁵. It’s even possible that this muted stress response is related to opioids’ addiction potential⁷.

Does buprenorphine treatment interfere with the endocrine system?

Opioids can cause endocrine dysfunction in many ways, so it’s natural to wonder if buprenorphine treatment runs the risk of causing hormone imbalances too. Like other opioids, buprenorphine can affect the endocrine system and hormone production.

However, buprenorphine is a partial opioid agonist, meaning it does not activate the brain’s opioid receptors as efficiently as full opioid agonists, like oxycodone and heroin. As a result, buprenorphine has reduced endocrine effects compared to most other opioids, so it’s safe to use as a treatment for opioid use disorder. 

Buprenorphine can still cause some of the typical opioid side effects and may change the way your body produces hormones, so it’s crucial to work closely with your treatment specialists to ensure that your hormone levels look normal throughout treatment². If anything is amiss, your care team will be able to help you find the proper treatment to normalize your hormone production.

Any of the above effects of opioids on the endocrine system may occur while taking buprenorphine, so keep an eye out for mood changes, muted responses to stress, fluctuating libido, and changes in your metabolism and digestion². 

Some men may experience erectile dysfunction, infertility, or difficulty reaching orgasm as a result of the use of buprenorphine. For many women, it’s common to experience a decreased sex drive while undergoing buprenorphine treatment, and the drug may disrupt menstrual cycles. 

Work with a dedicated team to get answers for all your treatment questions

Opioid use disorder and the medications used to treat it can have wide-ranging effects in the body—and we know how confusing these changes can be. That’s why Ophelia pairs patients with dedicated care teams who can provide comprehensive care and support for all the questions you didn’t even know you had.

Get to know our clinicians and find out how our programs work.