How to Fight Carb Cravings by Boosting Brain Serotonin

By Michael A. Smith, MD

Serotonin is known as the “feel good” neurotransmitter. It plays a central role in mood stability and helps promote feelings of security, relaxation, and confidence.

There’s evidence now that serotonin may even play a role in carbohydrate cravings. As a matter of fact, low brain serotonin has been linked to carb binging and overeating that contributes to excessive body fat.1

So if you’re looking for more ammunition in your battle against carb binges, you should probably keep on reading.

Tryptophan Enhances Serotonin Production

Tryptophan is the precursor to serotonin, and supplementing with tryptophan enhances the production and function of serotonin in the brain.

In fact, human studies suggest that obese patients have diminished plasma tryptophan levels that remain low, independent of weight loss or diet.2,3 This altered tryptophan metabolism reduces serotonin production and contributes to carb cravings and binge eating.

At this point, tryptophan probably sounds like an easy solution for carb bingers, right? Not so fast — there’s a problem to consider: Unfortunately, tryptophan is easily degraded and most of it will never even get the chance to convert into serotonin.

There’s good news though — we’ve actually figured out a way to protect tryptophan in an oral supplement. How? By combining it with lysine and nicotinamide. As it turns out, the presence of these two additional nutrients helps get tryptophan to the brain to readily convert into serotonin.

Saffron Helps Naturally Maintain Serotonin Levels

If you can’t help reaching for that extra cookie or you’re having a hard time with between-meal snacks, you might also want to look at saffron. Saffron was actually used in ancient Persia as a way to enhance mood, relieve stress, and curb appetite.

Two compounds in saffron, safranal and crocin, have been shown to modulate serotonin activity in the brain.4-6In more recent studies, women taking a patented saffron extract reported the following results:7

  1. Reduced desire to snack
  2. Fewer instances of carb binging between meals
  3. Less hunger
  4. Moderate weight loss
  5. More energy
  6. Improved mood

The Influence of Exercise on Serotonin Levels

According to the National Institute for Health and Clinical Excellence of the United Kingdom, exercise actually increases brain serotonin function in humans. An unrelated 1996 animal study revealed that there are two mechanisms by which physical activity increases brain serotonin.

First, exercise increases the rate and frequency at which serotonin is "fired" within the brain, resulting in an increase in both serotonin production and release. Second, regular exercise increases the level of tryptophan in the brain.8

Although the exact mechanism is not completely understood yet, one thing is clear: Exercise improves serotonin activity in the brain. As if you needed another reason to exercise!

Eat Less & Feel Better

If you’re trying to lose weight but binge eating is holding you back, you may want to try optimizing your brain serotonin levels as an additional approach. Who knows, maybe you’ll end up feeling better and eating less.

Want more information on managing serotonin? Check out this Life Extension article for additional insight: Why Serotonin Levels Decline With Age.

Have anything to ask or add? Please join the discussion in the comments!


  1. Eating Disorders: A Reference Sourcebook. Lemberg R. Ed., Oryx Press; 1998:51.
  2. Am J Clin Nutr. 2003 May;77(5):1112-8.
  3. Curr Drug Metab. 2007 Apr;8(3):289-95.
  4. BMC Complement Altern Med. 2004 Sep 2;4:12.
  5. J Ethnopharmacol. 2005 Feb 28;97(2):281-4.
  6. Prog Neuropsychopharmacol Biol Psychiatry. 2007 Mar 30;31(2):439-42.
  7. Nutraveris; 2006. Unpublished study.
  8. Behav Pharmacol. 1996 Jan;7(1):101-104.


Anonymous said...

P5P also helps modulate serotonin levels significantly.

Life Extension said...

Did you mean 5-HTP? If so, that's correct. Tryptophan crosses into the brain and converts into 5-HTP, which then converts into serotonin.

Anonymous said...

For those with reduced kidney function, is there a safe alternative to saffron, which I've read should not be used?

Life Extension said...

Tryptophan or 5-HTP may help. They are the precursors to serotonin.

Anonymous said...

I wish they would just sell antidepressants over the counter. They are not abused. There are a couple really safe ones for taking before sleeping. Paxil,in a milder dose, is super gentle. It just helps you sleep better.I think America is very dog eat dog industrial nation. There is too mush stimulation and pressure.More serotonin is a great idea!

Anonymous said...

I went to an support group for overeaters and found that 99% had severe sleeping problems - just like me. One of the meds my doc put me on to get sleep was 5-HTP (and 3 others). If anyone can answer the following I would be SO grateful: If fluctuating levels of neurotransmitters result in the brain fighting to get to normal levels by binge eating carbs can you really say this type eating "disorder" is an addiction? And really is it even a "disorder". It seems like an incredibly functional way for the brain to try to heal itself. Your very own personal neurologist so to speak. Granted, the end results may be obesity so this is not a well trained neurologist but at least he/she is trying. This seems like it could be a rollercoster ride for a person with bi-polar disorder. The brain constantly trying to adjust resulting in periods of binge eating and periods of deminished desires for food. I write this based solely on my experience with addiction to cigarettes (quit 8 years ago) as compared to my problems with food. A profound difference. Cigs - clear cut addiction 24/7. It never turned itself on and off. Stayed ON always. Even 8 years smoke free and there are moments when my body craves it. But like with other addictions I do not worry because all I have to do to never smoke again is to simply NEVER pick up the first one... ever! Food addiction, for me, turns itself on and off. There is nothing 24/7 about it. I went for 3 months in a massive dangerous binge of carbs where I cried trying desperatetly to stop and failed over and over. Blood sugar numbers 400+ at morning fasting test. Then like so many times before, some random night I go to sleep and wake up the next morning and it has all stopped. Before even opening my eyes I know the binging was gone and I was free- again. As though a switch was flipped in my brain during sleep and all is well now. I am on day 32 of being free from that insanity. I have zero desire to binge eat. I can eat what some would consider trigger foods (carbs) and it has no dangerous effect on me. Right now I have the freedom to eat like a normal healthy person who has no food issues - a beautiful peaceful feeling. Yet behind the peacefulness I know the switch will flip again eventually and my peaceful freedom will be taken away from me again. No doctor has ever been able to explain to me what this is. A therapist says it is a case of classic food addiction. If it is then why does it turn itself off in such a dramatic way and has done so for years? Like I said cigarette addiction NEVER did that. Makes me wonder why neurologist do not treat eating disorders rather than therapists. Based on my experience the cure is much closer to neurotransmitter issues than it is bad days from my childhood.

Anonymous said...

I have been taking L tryptophan opti pure from Life Ext for mostly 6 months, as well as ashwaganda and occasionally L theanine. In addition I take Sam E plus extra B vitamins/folic acid etc. I take these for insomnia, anxiety/depression. My problem is deciding on what the correct dosages are for maximum benefit to me and what needs to be taken daily. From what I have read, these can work and to an extent I believe they are but the troublesome part is the dosing and figuring out what works and what does not. I have previously started with just 5HTP in the evening but was advised to try L Tryptophan.

Life Extension said...

We believe that the natural methods for optimizing serotonin levels are safer and just as effective as many antidepressants.

Life Extension said...

The desire for carbs will fluctuate because of many lifestyle and behavioral factors. And the latest neurotransmitter theory is pointing to low brain serotonin as the underlying culprit behind the behaviors and cravings. But we fully admit that it's more complicated than the effects from just 1 neurotransmitter. However, boosting serotonin in the brain is going to help!

Life Extension said...

Thanks for all of the comments! As a reminder, if you have specific dosing questions, please speak with one of our health advisors. They can be reached at 1-800-226-2370.

Bob Gordon said...

If levels of serotonin in the brain are responsible for food cravings, why do you suppose so many people taking SSRIs gain weight rather than lose it?

Life Extension said...

Great question Bob! It's because SSRI's are not "clean" drugs. They negatively influence many brain chemicals. This is why they have so many side effects.

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