Move more, remember more.
Aerobic exercise is the best-evidenced way to feed your brain more blood, and in trials thinking sharpened alongside it. It costs nothing, tops the ranked list of fixes here, ahead of the medical options and the function you stand to win back. What quietly drains it is on what hurts.
Start with the free ones.
Everything that lifts brain blood flow is also good for you, with almost no downside. If COVID hit your vessels, you are treating the cause directly. If it did not, you end up fitter, sleeping better and steadier. The list runs strongest evidence first.
The short version: move your body daily, gently if exertion crashes you, hold a fixed wake-up time, eat for the vessels, and treat high blood pressure.
1 Move your bodythe biggest free win strongest
How it helps Aerobic training is the best-evidenced way to raise resting brain blood flow: in one trial it lifted frontal-lobe flow by about 27 percent, and thinking sharpened alongside it.1 Walking, cycling and swimming all count, and the bonus goes to whoever picks one hour and keeps it.2
The catch If exertion leaves you wiped out for a day or two afterward, that is post-exertional malaise, and pushing through makes it worse. Start small, recover, add a little, and with POTS begin lying down and lean on fluids and salt.3
2 Keep your blood pressure in rangethe small vessels' main protector best proven
How it helps High pressure is what damages the small penetrating arteries that fail in small-vessel disease, which makes steady control the single best-proven protector of the brain. In the SPRINT trial a lower target cut mild cognitive impairment and slowed white-matter-lesion growth, and the tighter control did not starve the brain, flow held steady.45
The catch Smooth, steady control matters more than chasing the lowest possible number, so if yours runs high, treat it with your doctor rather than adjusting anything on your own.6
3 Protect your sleepfix the wrecker, hold a wake time foundational
How it helps Sleep is when the brain clears and resets, and any rhythm you keep feeds the flow. The one anchor worth holding is a fixed wake-up time, even after a rough night, with daylight in your eyes soon after, which does more than a fixed bedtime.
The catch Plenty of things wreck sleep, ADHD, anxiety, pain, shift work, so get whatever is doing it treated first. When you blow it, restart the next morning instead of writing off the week.
4 Eat for the vesselsthe lining that feeds the brain the pattern
How it helps What keeps the vessel lining healthy keeps the brain fed: leafy greens and beets, berries and cocoa, oily fish, and less ultra-processed food.7 The overall pattern matters far more than any single food.
The catch The better-studied single options work through the same vessels, dietary nitrate from beetroot, cocoa flavanols and omega-3, each lifting flow or vessel function modestly and most if your intake is low, never a substitute for the pattern.89
5 Slow your breathingtwo minutes, no kit free, fast
How it helps Carbon dioxide is the brain's own vessel-opener, so over-breathing tightens the vessels while slow breathing, around six breaths a minute, keeps them relaxed and the flow steady, a free two-minute reset.10 If an infection hit your lungs, the brain pays downstream, so diaphragm breathing plus a patient rebuild of fitness puts more oxygen into the blood before it reaches your head.
6 Regular heat, a saunawarm, often, observational promising
How it helps Regular passive heat tracks with lower dementia and stroke risk, dose-dependently: the largest reductions in the Finnish cohorts, around 60 percent, came with a genuinely hot sauna taken four to seven times a week.1112
The catch It is an association, and the one randomized trial found no change in vessel function, so copy the pattern but do not bank on it; overheating to the edge in a dry sauna acutely drops brain flow by about a third, while a hot bath holds it steady.1314 With POTS, ME/CFS or long COVID, heat triggers crashes, so keep it mild and brief.
7 Stay ahead of dehydrationavoid a needless deficit baseline
How it helps Being even mildly low on fluid makes the brain work harder for the same supply, so steady hydration just removes a needless drag, not a boost from over-drinking. For the head-rush when you stand, water plus more salt and waist-high compression keep blood from draining away from your head, if your blood pressure, heart and kidneys allow.
8 The free extrasnaps, daylight, people small wins
How it helps Small things stack: a 20 to 30 minute nap resets a tired brain, morning daylight fixes a wrecked body clock better than any supplement, sex is light cardio that also improves sleep, and time with people you like brings down the stress hormones that tighten your vessels. Losing deep visceral belly fat, the same movement-and-food work aimed at one target, eases the inflammation that stiffens brain vessels.15
The medical options, in depth
No drug is licensed to raise brain blood flow. There are prescription strategies that protect the small vessels, plus supplements, devices and standing-symptom care with evidence behind them, sorted below by how strong that evidence is. Take all of it to a clinician who knows your history.
Prescription, in use or in trials
Blood-pressure control is the best-proven brain protector. High pressure damages the small penetrating arteries that fail in small-vessel disease. In the SPRINT trial, aiming for a lower target cut mild cognitive impairment and slowed the growth of white-matter lesions, and the tighter control did not starve the brain, cerebral blood flow held steady.45 If your pressure runs high, this is the highest-yield conversation to have.
Cilostazol with a nitrate opens vessels and restores the nitric-oxide signal small vessels lose. In the LACI-2 trial of 363 lacunar-stroke patients the pair reduced a combined measure of further stroke, dependence, cognitive decline and death, with no safety alarms. It was a feasibility trial, so this is promising rather than proven, and the definitive trial is running now.16 Not standard care yet, one to raise with a stroke specialist.
PDE5 inhibitors, tadalafil and sildenafil, prolong the nitric-oxide signal that widens vessels, and the brain question here is badly under-researched. Low-dose daily tadalafil is now in wide use, approved for prostate symptoms and taken daily for erectile dysfunction, but popularity is not brain evidence. The only dedicated trial in cerebral small-vessel disease, tadalafil at 20 mg daily for three months, was poorly tolerated and showed only a borderline, non-significant hint of less white-matter damage and no cognitive gain; its authors call for larger trials at lower doses.17 The widely shared claim that these drugs prevent dementia rests on observational data,18 and is contested: the men who take them are healthier to begin with, erectile function is itself a marker of vascular health, and the most rigorously controlled study found no protective effect.19 The mechanism is sound; the drug is not proven for the brain. Never combine these with nitrates: together they can cause a dangerous drop in blood pressure.
Metabolic drugs, the GLP-1 agonists such as semaglutide, were linked to roughly half the rate of dementia or cognitive impairment in a 2025 review, though that is a secondary signal mostly in people with diabetes or obesity.20 Reassuring if you already take one, but the brain signal alone is not a reason to start one.
For long COVID specifically, low-dose naltrexone has the most consistent signal for fatigue and brain fog, from small uncontrolled studies with low certainty and no completed randomised trial yet.21 It is a prescription drug compounded at low doses, so it is one to start with a clinician, not to self-source. The popular blood-thinner approach aimed at microclots is not supported and carries bleeding risk.
Attention and wakefulness drugs are not perfusion drugs, though they are often assumed to be. Atomoxetine, a noradrenaline reuptake drug used for ADHD, sharpens the brain’s attention network but does not reliably raise resting blood flow: direct ASL-MRI shows mixed regional changes, including falls in the midbrain and thalamus, and in Parkinson’s it restored the response-inhibition network with no change in perfusion at all.2223 Modafinil shifts flow by region too, up in some areas and down in others, tracking alertness rather than supply.24 The reason is mechanical: noradrenaline can tighten the smallest vessels as readily as open them.25 They can be the right call for attention or daytime sleepiness. Just do not expect them to feed the brain more blood.
Supplements with real evidence
Most rest on single trials and measure blood flow on a scan rather than long-term benefit, so keep expectations modest. The better-supported ones: resveratrol raised resting brain blood-flow velocity and vessel responsiveness in postmenopausal women, with small cognitive gains.26 Dietary nitrate from beetroot, cocoa flavanols and omega-3 each lift perfusion or vessel function modestly, most if your intake is low.789 B vitamins earn their place only if your homocysteine is high: in that group they halved the rate of brain shrinkage in mild cognitive impairment, so test first.27 Ginkgo eases established dementia symptoms but does not prevent dementia in large trials,28 and vinpocetine should be avoided in pregnancy.
Devices and procedures
Hyperbaric oxygen is the contested one. A forty-session sham-controlled trial improved cognition and fatigue,29 but a rigorous shorter course found nothing over a convincing sham,30 and it means roughly forty daily sessions at high cost, so treat the marketing with caution. Enhanced external counterpulsation, pulse-timed leg cuffs, improved fatigue in a small uncontrolled long-COVID group.31
For the dizziness on standing (POTS)
Much post-COVID fog on standing is orthostatic intolerance, where blood pools, brain supply drops and the heart races. Start without drugs: more fluid and salt if your blood pressure, heart and kidneys allow, waist-high compression, and a recumbent-first exercise rebuild on a rower, a recumbent bike or in a pool. Most people who complete that programme stop meeting the criteria for POTS.32 If that is not enough, drugs matched to your pattern come next with a clinician: ivabradine or low-dose propranolol to slow the racing heart, midodrine, droxidopa or fludrocortisone for pooling and low standing pressure. One rule that is not optional: screen for post-exertional malaise first. If you crash a day or two after overdoing it, that is post-exertional malaise, and push-through exercise can do lasting harm, so pace within your limits and rebuild in tiny steps.
Even if COVID never touched you, this pays for itself.
Whether or not the virus is the reason your brain feels under-supplied, two things protect brain blood flow: staying aerobically fit and keeping blood pressure healthy. The same machinery that feeds a working brain also guards your mood, your energy, your heart and how long you live. You are buying back years of good function.
Effect sizes come from varied study quality and most are associations rather than proof of cause, but the direction is not in question.
That is the upside. What quietly spends it, the substances and the conditions worth treating, is on what hurts. If your symptoms are worst on standing, see standing intolerance.
Keep your brain better supplied.
Most research on cerebral blood flow stays locked in journals, behind paywalls and jargon, far from the people it could help. The newsletter reads it for you and sends only what changes what you can do: a new way to raise your own blood flow, or a finding that moves the advice on this page.
The list is not open yet. It opens with the first issue. A few emails a year, every claim sourced.