Prolactin is a peptide hormone produced by specialized cells, called lactotrophs, located in the anterior pituitary gland at the base of the brain. The main physiological function of this hormone is to stimulate and sustain milk production after childbirth. Prolactin also plays a role in reproductive function, metabolism, and immune response. Hyperprolactinemia is the medical term used to describe abnormally high levels of prolactin circulating in the blood. Normal prolactin levels generally fall below 25 nanograms per milliliter (ng/mL) for women and below 20 ng/mL for men, though laboratory ranges can vary. This condition can lead to symptoms such as irregular menstrual periods, infertility, and spontaneous milk discharge (galactorrhea) in women, or reduced libido and hypogonadism in men. Effectively lowering prolactin levels and resolving associated symptoms requires correctly identifying and addressing the specific underlying cause of the elevation.
Identifying Underlying Causes
The initial step in normalizing elevated prolactin levels is determining the source of the hormonal increase, as treatment must be tailored to the specific etiology. Hyperprolactinemia can result from physiological states, pharmacological side effects, or various pathological conditions. The most common pathological cause is a prolactinoma, which is a non-cancerous tumor that forms in the pituitary gland and overproduces prolactin. These tumors are categorized by size, with microprolactinomas being smaller than one centimeter and macroprolactinomas being larger. Prolactinomas often require targeted treatment to reduce both the hormone level and the tumor size.
Medications represent another frequent cause of persistently high prolactin levels. Many drugs can interfere with the brain’s dopamine signaling, which is the primary inhibitory control system for prolactin secretion. Common culprits include certain antipsychotics, antidepressants like selective serotonin reuptake inhibitors (SSRIs), and some anti-nausea medications. Treatment involves adjusting the dosage or substituting the medication under the supervision of a medical professional.
Systemic diseases and physiological states can also lead to hyperprolactinemia. For example, primary hypothyroidism, a condition where the thyroid gland is underactive, can cause elevated prolactin because the body increases thyrotropin-releasing hormone (TRH), which also stimulates prolactin release. Chronic kidney disease, which impairs the clearance of prolactin from the body, is another non-pituitary cause. In these situations, treating the underlying systemic disorder, such as initiating thyroid hormone replacement therapy for hypothyroidism, usually resolves the prolactin elevation.
Prolactin secretion increases in response to physiological stimuli. Events like acute stress, sleep, chest wall irritation, and vigorous exercise can temporarily raise prolactin levels. Identifying whether the cause is a tumor, a medication, or a systemic issue guides the next steps toward normalization.
Pharmacological Interventions
When hyperprolactinemia is caused by a prolactinoma or is significantly elevated and symptomatic, the standard medical approach uses prescription medications known as dopamine agonists. These drugs function by mimicking the effect of naturally occurring dopamine, which normally acts to suppress prolactin production and release from the pituitary gland. They bind to D2 receptors on the lactotroph cells, effectively shutting down the overproduction of the hormone.
The two most common dopamine agonists used are Cabergoline and Bromocriptine. Cabergoline is favored because it is more effective at lowering prolactin levels and is usually associated with fewer adverse effects. Its long half-life allows for convenient once or twice-weekly dosing, which can improve patient adherence. Conversely, Bromocriptine is an older medication that requires daily or twice-daily dosing due to its shorter duration of action.
Both medications are highly effective. For patients with prolactinomas, dopamine agonists are also effective at causing the tumor to shrink, which can alleviate symptoms like headaches or visual problems caused by the tumor pressing on surrounding tissues. Treatment response is monitored through regular blood tests to track prolactin levels. In cases of prolactinoma, magnetic resonance imaging (MRI) scans are also performed periodically to assess any reduction in tumor size.
Treatment duration is individualized based on the patient’s response and tumor shrinkage. Patients who cannot tolerate the side effects of one dopamine agonist, such as nausea or dizziness, may be switched to the other, or the dosage may be adjusted. These medications require strict physician oversight due to potential side effects, including a rare risk of heart valve issues, especially with high, long-term doses.
Supporting Lifestyle and Dietary Strategies
Certain lifestyle and dietary changes can support overall hormonal balance and help manage mild hyperprolactinemia. Implementing consistent stress-management techniques, such as mindfulness meditation or ensuring adequate sleep hygiene, can help reduce the sustained level of stress hormones like cortisol, which indirectly supports prolactin regulation.
Dietary choices can play a supportive role in optimizing the body’s hormonal environment. Prolactin secretion is inhibited by dopamine, and certain nutrients are required for the body to produce this neurotransmitter. Vitamin B6 is necessary for the synthesis of dopamine and has been shown to exert a dopaminergic effect that can help reduce prolactin levels. Foods rich in Vitamin B6 include bananas, fish, chicken, and spinach.
The trace mineral zinc is important in maintaining hormonal balance and may help regulate prolactin. Incorporating zinc-rich foods, such as cashews, lean meats, and chickpeas, supports the body’s function. Minimizing the consumption of highly processed foods and refined sugars is also recommended, as maintaining stable blood sugar levels can prevent hormonal imbalances that might contribute to prolactin elevation.
Avoiding unnecessary physical stimulation of the chest area is an effective strategy, as nipple stimulation is a direct physiological trigger for prolactin release. This includes avoiding overly restrictive clothing or excessive mechanical stimulation of the area.