Vasodilation vs Vasoconstriction

Hello sciency-LCers! I have been reading a bit here and there about the role of the endothelium after watching Gez Medinger's videos a while ago. When I look into supplements or treatments that might help speed the repair the endothelium, it seems things like Pycnogel are vasodilators. I've taken a few of them and they tend to make me feel worse and not better, likely because of my Covid-induced POTS. So far the thing that has helped me feel a lot better is a prescription for Ivabradine, which (as I understand it) constricts a part of the heart to slow my heartbeat and help it be more efficient in the conveyance of blood.

I'm not asking for medical advice so much as asking if anyone can help clarify this tension between the vasodilation that seems to help support endothelial repair and the constriction that helps with POTS treatment? Or is this kind of a chicken and egg situation where the POTS-like symptoms could have been caused by endothelial damage?

Any research you could point me to would be much appreciated as I try to learn more. Thanks!


I have this same question. I feel like the supplements that help blood flow usually dilate blood vessels and lower blood pressure. I tend to feel much more weak directly when I take them, exercise tolerance reduces, and sometimes other symptoms can flare like anxiety or racing heart. On the other hand, I think they have overall improved my condition. The endothelial damage itself is due to ongoing inflammation or damage from previous inflammation during illness. And so it seems logically that more blood flow and opening up all the vessels, especially tiny ones like capillaries, is necessary to allow the body to heal and repair all these tissues, Also, this process would take a very long time - there are miles of capillaries and Covid can wreak widespread damage, so the body is working really hard to repair all those cells. It's my belief that these supplements are helping, but its very frustrating to realize that I can't know that for sure. I think it's not totally understood what causes POTS. There could be multiple reasons in Long Covid and different patients have different versions. 1) It seems for sure one reason is inflammation in the central nervous system (brain, brainstem, spinal cord): inflammation in the brainstem means the autonomic nervous system doesn't function properly, therefore it doesn't regulate vasodilation and vasoconstriction, blood pressure, heart rate etc in normal ways. This would be like the boss of the company has a nervous breakdown or something - the central authority is dysregulated and so functioning of the system is off. 2) It follows logically to me (I didn't read this anywhere, just my understanding) that if all the endothelium of all the blood vessels in the body are damaged, there is basically a structural integrity issue. So this would mean that the vessels are not strong enough to constrict the way they should to bring blood flow back up to the heart. Or that they lack cellular components to send and receive signals from the nervous system. On top of that, many small blood vessels are clogged by inflammation or thickened blood full of microclots, so they are basically offline. So the blood vessels are weakened, lack structural integrity, do not respond to signals, and there are fewer of them. Thus the body tries to regulate itself with proper blood flow and tissue oxygenation but struggles to do so until these tissues have repaired, which takes months or years, as there are miles of endothelium and the cells take time to regenerate. Therefore, I think time is the most important thing and maybe the supplements help but it's not clear. It's worth trying them as some people get so much better, but if they make you feel worse and something else makes you feel better, it seems important to feel better and be functional. If the body is able to get blood flow somehow, it should eventually heal and repair some of the damage to the endothelium. It might be that there is some permanent loss of function just because not all the blood vessels that were lost can be grown back, so after Long Covid there may be just a long-term reduction in the body's ability to regulate blood flow and tissue oxygenation around the body. But each person's mix is so different. For some inflammation in the nervous system is the whole ball game. For others, endothelial damage and lack of blood flow from microclots is a bigger deal. That's my guess as to why different things work for different people. Have to follow our intuition a lot of time and just make the best guess for staying stable and functional.


Thanks for the insightful reply, I appreciate it! I think you've captured the issue well. I am trying to figure out my tolerance for potential/observable symptom regression and weigh the pros and cons for trying out some of these supplements. It's a tricky thing to manage as I am finally able to work almost full time hours and I don't want to compromise that, though I would also love to have the energy to be able to have a more full life outside of working. I feel like my Ivabradine prescription is basically helping to address issue 1 above, and your concentration on increased blood flow for the endothelium makes a lot of sense. Perhaps staying the course with Ivabradine, since it's helped me a lot, and cautiously/slowly including more movement/exercise to stimulate blood flow might be a good way to go for the near term, and perhaps finding some anti-inflammatory support via supplementation or food could support that.


Yes definitely that sounds like a good way to go. Good luck!


Thanks, you too!


I notice this the most during exercise for the most part I’m 90% healed but something happens when I exercise that I feel not myself. For instance I can feel the veins in my nostrils constrict when I’m running to a point I can’t breathe through my nose, when I start walking it begins to reopen. I feel this is also happening within my brain so I get brain fog after exercise, because the blood flow is not circulating properly. Or maybe something with oxygen not circulating properly either. I’m on natto/ldn but I am determined to figuring this out. I think you are right with endothelial damage and that the vagus nerve is out of whack. No idea how long it takes to heal tho and if I should do absolutely no movement or try to keep pushing my abilities.


I have pots like symptoms and have noticed the same with vasodilators.


Sorry to hear! It's frustrating to find that things which seem to work for others don't work for me, but good to know I'm not alone. Thanks!


Basically, the higher my heart rate is the worse I feel. During my crashes my resting heart rate measured on my fit bit will climb, even only a few bpm. And take weeks to settle down. Going into a cold room seems to drop my heart rate and I feel momentary relief. But the cold burns more calories and is harder on your heart and body. I'm guessing the cold causes vasoconstriction. Alternating cool and warm is probably best but I don't have much energy at all right now.


I notice whenever my heart rate gets above 160 I’m in for an onslaught of symptoms typically after a workout. I gotta keep my heart rate in zone 2. Also if I don’t workout for a few days my endurance plummets so my hard works harder to less and im at square one again smh.


How does coffee affects you? Also, go take a read on sympathetic nervous system and parasympathetic. It's like many dysautonomia symptoms here happens because of an overactive sympathetic but there are people who have symptoms of an overactive parasympathetic


I'll take a look, thanks!


Oh, and I find coffee sort of confusing. It definitely increases my heart rate, but I don't find it to make me feel worse overall. I'm guessing that's because it's a vasoconstrictor.


I saw a few people (male and female) having success with viagra as a vasodilator. Not kidding