High Prolactin Causes Severe Fatigue.


I wrote this elsewhere a few years ago and am still wondering how high prolactin figures into this whole disease process.
Just recently, I read something by TS Wiley (I know, I don't agree with her views on BHRT either) that indicated that high prolactin is a sign of an overactive immune system. Her idea (paraphrasing) was that the mother needed an especially active immune system in order to pass along antibodies and immunity to the new baby. Elevated prolactin levels are apparently a part of that and reflective of the activated immune system.

So what causes the excessive immune activation? And is it really excessive...or is actually fighting some not yet identified pathogen? Million Dollar Question, right?

I'm sure that this won't be applicable to everyone with ME/CFS but I thought I would share my experience with high prolactin thus far just in case it could help someone else.

I've had mildly elevated and top of the range prolactin for a couple of years now. I've never thought much about it because most doctors agree that prolactin needs to be in the 100s before it signifies a pituitary tumor. The normal level is 4-30 ng/mL for females (lower for males). However, most reproductive endocrinologists look for a prolactin level lower than 15.

But recently, I started having some symptoms and thought I would do some more reading on the topic.

It turns out that having even mildly elevated levels of prolactin can cause severely debilitating fatigue.

Not only that it can also cause migraines, low sex drive, and cognitive difficulties (probably due to low dopamine). Prolactin and dopamine seem to have an inverse relationship - when prolactin is high, dopamine in the hypothalamus particularly seems to be low. Drugs for hyperprolactimia are usually dopamine agonists like bromocriptine or cabergoline. Some people also have luck using Deprenyl. There is also a study using American Ginseng (which is a less stimulating form of ginseng than Siberian supposedly) to lower prolactin levels.

Prolactin also stimulates autoimmune diseases and there are studies showing that symptoms of diseases such as rheumatoid arthritis and lupus improved by lowering prolactin levels. Prolactin heightens the response of the cellular arm of the immune system (Th1 imbalance).

If you are hypothyroid, you will likely also have high prolactin because they are both regulated in part by TRH from the pituitary. This is a double whammy for anyone trying to lose weight. High prolactin makes it nearly impossible to lose weight. I believe this is because a nursing mother would not be best served to lose a bunch of weight while trying to feed her baby.

Prolactin also seems to be associated with low progesterone and short luteal phases in the menstrual cycle. Women trying to get pregnant are often given drugs to lower the prolactin level because it is almost impossible to conceive with high prolactin.

I have a mildly elevated prolactin level, a very low testosterone level and high IGF-1. This apparently is a clinical picture associated with a pituitary tumor (which are almost always benign) so I am having an MRI (3T) at the end of the month and then I'm starting on prolactin lowering meds to see if I can't straighten this out. My mother keeps telling me that people pay big money to get bigger boobs, but I am SO over it already! :)

So if you struggle with extreme fatigue, weight gain/inability to lose, and low motivation and cognitive function, it might be worth having your prolactin tested to see if this is an issue for you. If you've gotten your other hormones right and are still struggling, it's worth a shot!


Well-Known Member
Given that this disease seems to involve both disturbance of hypothalamic/pituitary function and immune activation, it's hard to know where the prolactin in the blood is coming from. It acts as a hormone on target organs when secreted from the brain, but as a cytokine on immune cells (leukocytes express PRL receptors and also secrete it). I don't think there is any discernible difference in prolactin derived from the two sources.

I had my prolactin and testosterone measured about a month after ME onset. Prolactin was high and testosterone was low. About five months later I had both measured again and prolactin was even higher and testosterone even lower. About 5 months after starting on antivirals, I had both measured again and the prolactin had come down below where it was initially, though it was still outside of normal range and about twice what it should be in someone my age/sex. I don't think there is much to be done about it specifically, it's just yet another sign of the underlying ongoing immune insult.


t's just yet another sign of the underlying ongoing immune insult.
But is it a sign of an immune insult or deficiency or a sign of an overactive immune system?
The treatment strategy would be quite different in the second case as one would want to calm the cytokines rather than try to stimulate them with herbs etc.
It's a mystery still.


Well-Known Member
But is it a sign of an immune insult or deficiency or a sign of an overactive immune system?
Depends on the situation. In a population that is known to have evidence of ongoing infection, it's probably the former. In SLE, MS, or RA patients (who also have elevated prolactin) it might be the latter.


In a population that is known to have evidence of ongoing infection
I'd say that's the million dollar question, right there.
There's a lot of evidence for infection in MS and RA too...but it's the same evidence unfortunately that relies on antibody testing and not detection of the actual pathogen.

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