Hi everyone, I just want to give my experience with this same exact issue.
First of all, I've noticed that for almost every single person with this issue it all started with a period of prolonged stress, and that's exactly how it was for me. During college I was consuming a lot of caffeine, getting barely sleep (~3-4 hours a night), not eating much, taking wayyy too many credits, and dealing with stress from my social circle. That's when the pounding started, I remember sitting in a hallway studying before an exam and I honestly thought that there was an earthquake occurring, my heart was pounding so extremely forcefully. Ever since then I've dealt with the pounding non-stop 24/7, sometimes it was so bad as many of you know that it will visibly shake my body and it's a constant issue.
Now sometimes about a year ago I got extremely sick with a strong fever and bad joint pain/inflammation, I started taking two grams of ibuprofen a day for about 4 days until the sickness subsided. Now, the ibuprofen helped with the fever and joint pain but I was extremely surprised that is DRASTICALLY helped to reduce the heart pounding to the point where I could barely feel it, I would have kept taking the ibuprofen for this issue but unfortunately it was giving me ear pain and tinnitus and within two days of discontinuing the ibuprofen the pounding started to resume.
Now, why would Ibuprofen help so much? Well it lowers norepinpehrine which is most likely the cause of the pounding for the vast majority of us, here's a video of a doctor explaining the issue -
. This doctor had the exact same issue and a lot of his clients report the same problem of the consistent 24/7 heart pounding, now he refers to the issue as "adrenal fatigue" but a more accurate description of the issue is either "HPA axis dysfunction" or "autonomic nervous system dysfunction". Study on ibuprofen lowering norepinephrine -
http://www.asaabstracts.com/strands/asaabstracts/abstract.htm?year=2014&index=2&absnum=3975.
Not going to get into this too much and I'm sure a lot of you are aware of HPA axis dysfunction but, basically what happens is chronic stress elevates cortisol -> causes brain damage (especially hippocampus cell death) -> important body hormones such as Testosterone/estrogen/progesterone/thyroid all fall -> Body then uses norepinpehrine as one of it's main fuel sources. There's more to it, but basically prolonged stress causes a messed up hormonal situation in the body and then norepinephrine rises as a final resource for fuel. Norepinephrine is the main hormone that dictates the FORCE of the heart beat, so if it's elevated you're going to feel the heart pounding that we all experience.
Anyways, we all need to lower norepinephrine and do things to actually help this heal, the easiest thing to do is to get on testosterone replacement therapy as I guarantee that almost everyone with this issue has incredibly low testosterone (both men and women), and increasing testosterone can heal HPA axis dysfunction and it has properties that directly lowers norepinephrine. But of course this isn't possible for everyone.
The thing that we ALL need to do is lower inflammation to help the body and especially brain to heal, the best things to heal this and things that I've found to work (and a lot of you have found to work) are below -
1. Ibuprofen is by far the best thing I've found, if I could tolerate it without side effects I would take it non-stop,
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4930904/ , here's a study showing how it helps to prevent PTSD symptoms from chronic stress and the HPA axis dysfunction that follows.
https://pubmed.ncbi.nlm.nih.gov/30586639/ and another showing it how it prevents depression symptoms from chronic stress.
"Chronic stress increases Corticosterone (Cortisol in humans) levels, which then decreases BDNF and induces apoptosis (programmed cell death) in hippocampal neurons. This loss of neurons in the hippocampus is thought to be significantly responsible for anxiety and depression seen after chronic stress exposure.
Ibuprofen is known to inhibit the pro-inflammatory gene iNOS (inducible Nitric Oxide Synthase), which is activated by Corticosterone/Cortisol - Nitric Oxide (NO) causes inflammation and oxidative stress in the brain, in the context of depression. This reduction in NO levels restores BDNF levels. BDNF then induces hippocampal neurogenesis, leading to reversal of the stress-induced depression and anxiety like behaviors.
In chronic use, however, Ibuprofen is toxic to the gut, kidneys, and heart. A better alternative would be Agmatine. Like Ibuprofen, Agmatine inhibits iNOS, but unlike Ibuprofen, Agmatine has no known organ toxicity with long-term use. Agmatine also demonstrates
significant antidepressant and anxiolytic effects in rodents."
2. Agmantine Sulfate - incredibly good at reducing the heart pounding at 1 gram a day and has studies supporting it's ability to prevent HPA axis dysfunction, it can be stimulating so take it early in the day (if you take it late at night it can cause sleep issues which will just make the situation worse). This has strong vasodilation properties so you may notice a slight increase in the pounding at first.
3. Ashwagandha - for me it needs to be a high dose around 2 grams a day of KSM-66 but this can directly raise thyroid hormone and testosterone which helps to antagonize Norepinephrine and help the body heal, also has a lot of studies to support it
4. High doses of Vitamin C - Around 1 gram a day
5. Taurine at least 6 grams a day spread out in 2-3 doses - Taurine directly inhibits norepeinpehrine, it lowers cortisol, decreases inflammation, also it NEEDS to be higher doses.
6. Minimum of 3 cups of spinach a day -
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262511/, not a supplement like the others but it has strong anti-stress properties, also a good source of magnesium and potassium which high stress hormones can deplete.
7. Mega dosing fish oil, I've seen some people mention in this thread that high doses helps to calm the pounding and it does this by directly lowering norepinephrine, Plasma NE concentrations were significantly decreased in the omega-3 group (from 1.49 +/- 0.39 nmol/L to 1.05 +/- 0.14 nmol/L) (
https://pubmed.ncbi.nlm.nih.gov/15925295/). Once again though, you NEED to mega dose this, like 10 grams+.
8. Phenibut - it's a calcium channel blocker and gaba b antagonist, it drastically reduces the heart pounding even more than a beta blocker for me, and it has more of a euphoric type of calmness compared to benzos, it's still a drug so be careful with this. Not only does it lower the heart pounding through calcium blocking, but it also directly lowers norepinephrine. There's some really bad stories of addiction and terrible withdrawls from phenibut but personally I haven't noticed any of that, nor have I even noticed much of a tolerance but everyone reacts differently.
https://www.sciencedirect.com/science/article/abs/pii/S1043661815301225 - study showing how it increases BDNF in damaged brain regions. Don't take over a gram of this, I've noticed poor memory if I take doses too high.
9. HIIT (high intensity interval training) - Exercise is amazing for this issue, you'll have to find what form works best for you since everyone is genetically different but for me high intensity is the best, exercise raises serotonin and dopamine which will help you to stay calm in the day. Exercise also lowers brain norepinephrine which can be really helpful.
10. QUIT CAFFEINE - you will NOT heal from this issue if you're consuming caffeine, also caffeine consumption PREVENTS the anti-anxiety and norepinephrine lowering effects of exercise, it also prevents serotonin from rising during exercise. There's studying showing caffeine directly exacerbates PTSD/HPA axis issues as well, if you consume caffeine and deal with a pounding heart, quit it immediately.
Anyways, if I consume ~1 gram of agmantine sulfate, ~2 grams of ashwagandha, ~1 gram Vitamin C, ~10 grams of Taurine, eat lots of spinach, mega dose fish oil, take 1 gram of phenibut before bed, exercise regularly, and stay the heck away from caffeine the heart pounding is soooo light that I can barely feel it.
This is my experience with the issue, it's actually been life ruining at times and caused me a great deal of stress, the fact that it shakes your body when it's really bad means that even sleeping is difficult. There's other causes of heart pounding but I'm willing to bet that the vast majority of people are dealing with an HPA axis dysfunction, good luck everyone.