May 14, 2014

5-HTP, Serotonin and Parkinson's: A Wrap and a Request

After researching my two recent posts about 5-HTP as a therapy for Parkinson's non-motor symptoms, I'm convinced that something significant is going on here. That process has also given me an idea for reducing the danger of a serotonin buildup that could lead to serotonin syndrome, a potentially dangerous side effect.

Getting the Right Dopamine-Serotonin Balance
That first post detailed my positive experience taking a minimal dose of the OTC serotonin-booster 5-HTP. I'm sure the supplement has helped me avoid the common non-motor Parkinson's symptoms -- depression, insomnia, constipation, and deteriorating executive function.

Recounting the experience, I was reminded of the connection between dopamine and serotonin as sister neurotransmitters. Parkinsonians know that levodopa -- the "gold medal" med we take to restore the dopamine that Parkinson's destroys -- must be mixed with carbidopa so the levodopa can cross the the blood-brain barrier to become effective.

What's not as well known is that carbidopa plays the same role with serotonin. That's why people who don't have Parkinson's can take 500-1000mg of 5-HTP daily, while I risk overdosing if I exceed 100mg a day.

Neurologists and Parkinson's researchers have typically concentrated on dopamine's role in the disease. But newer studies are shifting the spotlight to serotonin. Two recent studies were particularly interesting:

  • A 2011 NIH study concluded that serotonin plays a significant role in executive function. The most unusual aspect of my 5-HTP use is how it kick-starts my executive function
  • A 2012 article in Scientific American discussed the use of skin grafts on Parkinsonians with severe symptoms. When the skin grafts took, the patients's dopamine was restored to near-normal levels, but the serotonin levels dropped below normal, exacerbating serotonin's PD-related non-motor symptoms. The authors suggested multiple skin graphs of both dopamine and serotonin for these severely afflicted patients. They also suggested that people with less severe symptoms might combine levodopa with "something else to boost serotonin function while possible."
For a few months, I've cut my basic 50mg pill of 5-HTP in half -- even quarters -- to determine if I could effectively distribute the dosage through the day. Several times, my walking seemed almost normal (not my usual old-man shuffle) and my handwriting became smooth, larger, and more legible (not my usual tiny, cramped, unreadable script). Unfortunately, I don't know what doses of levodopa and serotonin produced those pleasant results. 

It seems clear to me that the connection between 5-HTP and Parkinson's needs further study.

Minimizing the Safety Concerns about 5-HTP
My second post focused on 5-HTP's safety. A 2013 study by found little concern about 5-HTP's  side effects except for one item: the possibility of "serotonin syndrome" from overdosing on 5-HTP. That warning got my attention, since -- on two occasions -- overuse of the supplement caused blood pressure spikes that took me right into my local hospital's emergency room. The hospital staff seemed less concerned than I was.

A recent NIH report reassured me I don't have serotonin syndrome. When I learned that typical treatment for the syndrome is to stop using the supplement and spend 24 hours under medical supervision, I decided to take 24-hour 5-HTP holidays several times a month.

I'm more comfortable taking 5-HTP now than ever. I try to steer clear of giving advice on this blog, but I think it's a good idea that anyone using 5-HTP have a home blood pressure monitor and check their blood pressure a couple of times a day. Even if wasn't taking 5-HTP, I'd still be checking my blood pressure at home because of the danger we Parkies have of orthostatic hypotension.

I'll have more to say next week about orthostatic hypotension and my discontinuing  with my doctor's approval, the blood pressure pills I've been taking for decades

A New Study and a Request
I shared some of these thoughts about 5-HTP with members of the Parkinson's forum on HealthUnlocked. I received an interesting response that included a link to a case study about a novel approach to managing Parkinson's by administering 5-HTP and L-dopa, along with L-tyrosine, L-cysteine, and cofactors. The report indicates that when these substances are administered in proper balance "the long list of problems that can interfere with optimum administration of L-dopa becomes controllable and manageable or does not occur at all."

It's a lengthy report I want to study and discuss with my neurologist.

My request: I can no longer dismiss my positive experience with 5-HTP as a fluke. Instead, I see it as an example of the potential for breakthroughs in the treatment of Parkinson's by working on balancing serotonin and L-dopa. But there's not much information out there at least as far as my Googling shows.

I'll keep researching the issue and sharing my own experience. I'd very much like to hear from others. I may draft a format for collecting information. But for now, I'd appreciate hearing your comments on this post. You can include your name, remain anonymous, or give some alias.


Anonymous said...

Thank you for sharing your experience. I am interested because my mother has recently been diagnosed with Parkinson's and I'm trying to find out how to help her (doctor only gave her a Levodopa-based medication). While looking for information, I came across a research about administering 5-HTP (and others) along with L-dopa: Could contain helpful insights. All the best! Dana

Anonymous said...

After publishing this post, I decided to do more research on the study I mentioned in the post that's currently underway and involves using amino acids with 5-HTP and levodopa. Turns out the author of the report also owns the company that sells the amino acid and the FDA ordered the company to stop making unproven claims for the product as therapy for Parkinson's. The owner/author also has been the subject of several disciplinary actions from his state medical board. See
But I reread the report on the study and checked the footnotes and found support for the use of 5-HTP to work on getting better balance between serotonin and dopamine.