Sudden Caffeine Sensitivity

So in March I asked my doctor for Phentermine (an amphetamine like diet pill). I have had it before and it never bothered me. I took this pill, this time, and thought I was going to die. It was even the lowest dose. I got off that and I asked my doc if there could be changes in how I did on a drug at an older age and she said yes. I didn't think much of it.

But then I went on another drug that didn't work the same. I found myself after a few weeks with bothersome symptoms. Wet stools and diarrhea and heart palpitations. I got off the pill. Somethings did improve but I still had soft stools and diarrhea and heart palpitations.

I didn't get on to this until this week when I had a second cup of coffee (normally not a problem at all) and ended up with 6 hours of palpitations.

I decided I had solved the problem and decided just not to have the second cup of coffee. But yesterday I had a large extra soda (caffeinated) and lunch and suffered 2 hours of palpitations.

Today I decided to really cut back on the caffeine. I had only 1/2 my cup of coffee this morning. And that is it. A caffeine free soda and water. And I have had a palp free day.

It seems like someplace along the line, rather quickly, my body has become super sensitive to caffeine. I might have thought it was the second drug I was taking but I remember having that bad reaction to phentermine in march. Has anyone else had this or got more sensitive to caffeine as they age?

I don't know that I've necessarily gotten more sensitive to caffeine with age, but since I gave it up completely (more on that in a second), I've noticed that even a little bit will have a dramatic physical and psychological effect.

Some background: I gave up caffeine back in 2015 as an experiment. I asked my gyno why I was having severe breast pain at frequent random times instead of just at certain points in my cycle, and she explained that this could be related to ovarian issues (which were ruled out with a blood test) and caffeine usage. I decided to cut out caffeine for a month to see if it made a difference in the breast discomfort. Boy, did it! I almost never have breast pain any more. Sorry if that's TMI; just thought it was interesting to note.

The other significant change I noticed was a dramatic reduction in the physical symptoms of my anxiety (I have General Anxiety Disorder). I used to get heart palpatations over the most insignificant things. That stopped after I gave up caffeine. My resting blood pressure went down to the point that it's almost too low sometimes! Overall I felt much more calm and relaxed. I started sleeping better. That's why my temporary avoidance of caffeine has turned into a permanent one.

It sounds like the physical changes you describe (the palpatations going away) are very similar to my experiences. That suggests to me that caffeine can indeed have more of a physical effect than we realize. I used to think that I had a high tolerance because I could consume a lot of it without feeling any more awake than I did before. Apparently it was just stimulating me in other ways besides wakefulness.

As far as an increase in sensitivity? Hard to tell. But now that I've given it up, I have to be very careful. I take Excedrin for migraines, for instance. It's the only caffeine I consume except on the rare occasion when I give in and drink regular tea instead of herbal tea (and whatever minute amount is in decaf coffee). I learned the hard way not to take Excedrin before bed - not only was I awake all night, I had a full blown anxiety attack! Not good. So anyway, I'm not sure how sensitive I was before but I'm definitely highly sensitive now that I've given it up.

Hope that helps answer your questions.

I gave up caffeine shortly after my breakdown in 2012. It took two days of having a migraine for withdrawal, but after that it was pretty good. It decreased some of my anxiety.

I spoke to my doctor about it and she says it is a known phenomenon with age. They simply don't know why. Interestingly I did have a similar thing happen at 30 which I just remembered. Prior to 30 I had about 5 cups a day via work but I went away to school and had to stop that (because I didn't have a coffee machine) and afterward I could only have about 1 or two per day. I have discovered that having water can reduce the sensitivity.

Now that think about it a lot of people that are older than me do have decaf... but I always thought it was due to medication / health conditions.

This happened to my sister. She loved coffee and black tea and drank quite a bit of both with no problem. When she was about 50 she began having panic attacks after drinking caffeine. Like, out of the blue. She had to cut caffeine out of her diet.

I am 46. Another problem I am having could be explained by it. I am having wet stools and increased gut motility and caffeine is known to increase that. In fact, when I was a kid I had constipation and it was only upon my first cup of coffee that I found the key to stopping it. Now, I wonder if I have become more sensitive, is this being effected too?

I am considering that I am going to have to cut it out or drop the dose substantially.

Interesting - I just found this.

I am on a diet and a few weeks ago I had a non fasting blood sugar test and it was 79. That is low. Typically it is about 95 to 105 - fasting. I have known for sometime that when I go on a diet I have to go to the bathroom all the time which is due to lower glycogen stores from eating less food and less carb food. Glycogen seeps up water so when your body starts using glycogen stores the water is released.

I have noticed that when I am NOT on a diet, I don't have to go to the bathroom a lot because the water is stored with glycogen. And my water release is more normalized.

It is entirely possible that I am eating a low amount of carbs and simple sugars.

I did just have a liver test too and all was well but, it isn't necessarily about liver function it is about the liver having sufficient glycogen stores.

I have been going round and round trying to figure out my heart palpitations trying not to give up caffeine but I have had the most success on the days I have cut back on caffeine severely. If I could come up with a pattern it seems that the pattern is that I cannot have caffeine early in the morning without having any food. It seems that if I have caffeine after 2 PM and after I have eaten, it doesn't trigger palpitations. But still..it has to be moderate amounts. like under 100mg.

The theory at the moment is that my levels of cortisol has risen. I just had a saliva hormone test and both the early morning and late morning cortisol came back high. The early morning value was prior to having any caffeine. So if I have a large caffeine drink in the morning before eating... it triples or quadruples the amount of cortisol in me for most of the day. I am not even sure that the high cortisol doesn't cause me to get "stuck" in a high anxiety mode.

I am attempting to give up caffeine but I have LITERALLY gotten up ever day since the age of 14 and had a cup of coffee. Usually not eating for about 1 hour. This morning I cut the cup in 1/2 and I still had heart palpitations but, I got so sleepy I had to take a nap and after that nap.. I had zero palpitations.

Finally today.. 3 days after significantly cutting my caffeine.. I had zero palpitations. I am wondering if there is some build up effect as my palpitations seemed to lessen over a couple of days. But it took time to sort of get me down to a low dose.

Had a theory tonight that I am testing out...

What if, the batch of coffee that I have been using was somehow contaminated with more caffeine than it should have? I happened to run across an article that said that we cannot be sure exactly of how much caffeine is in any given cup of coffee because it will change based on cooking technique. And could, in theory, be over 100% more than we think.

Then I looked it up and I purchased a new batch of instant coffee on May 4th from Walmart and I had my first noticeable "attack" on May 17th. Also, I was wondering how long the batch might have lasted and it contains 120 servings. Even if I had more than one serving I could be using the same container that I was in May.

This could work... so far I don't really notice much of an issue from a second cup of coffee or tea that comes from outside my house and is consumed later in the day.

A lot of reports of people who get this report that the sensitivity seems to go away after a while...

I took out a new bottle and I took from that we will see if it works.

Well I am disappointed. I had two cups of coffee yesterday before work and had palpitations for about 4 hours from 11 to 3. I probably had about 25 per hour so I am thinking I had about 100 yesterday. I had great hopes on Sunday when I had zero paps but that day I had one cup.

On problem I am having is that my stools now are growing hard.

I need to have at least one cup of coffee to stay regular and that cup has to be in the morning but, it does cause palpitations. Not a lot but some.