- You breathe in through one nostril and out through the other, alternating, using your hand to close each side. In Sanskrit, it is nadi shodhana, and it is also sold as anulom vilom.
- Its best-evidenced effect is on blood pressure. A meta-analysis of six randomized trials found systolic pressure roughly 7 mmHg lower than control, which is a clinically meaningful drop.
- The claim it is most famous for — that it balances the two brain hemispheres — is the one that has been tested and failed.
- The attention benefit is shakier than it looks. In the study usually cited for it, sitting quietly did the same thing.
- It is the one technique on this site a timer cannot fully run for you, because it needs your hands.
What Alternate Nostril Breathing Is
You use the thumb and ring finger of one hand to close each nostril in turn, breathing in through one side and out through the other. In through the left, out through the right, in through the right, out through the left — that is one round. The Sanskrit name is nadi shodhana, usually translated as channel purification; anulom vilom is a closely related practice often used interchangeably.
The physiological starting point is real and slightly surprising: you are not breathing equally through both nostrils right now. One side is more open than the other, the dominant side switches every few hours, and this nasal cycle is a well-documented feature of human physiology rather than a yogic idea. What alternate nostril breathing does is override it deliberately, forcing airflow through whichever side your body has currently throttled.
What follows from that override is where the claims get ahead of the evidence, and that is most of what this page is about.
How to Do Alternate Nostril Breathing
- Sit upright and set the hand. Right hand, thumb resting beside the right nostril, ring finger beside the left. Fold the index and middle fingers into the palm or rest them between the eyebrows — that shape is called Vishnu mudra, and its only real function is keeping the two working fingers apart.
- Close the right nostril and empty through the left. Start on an exhale, not an inhale. This is the step people skip, and it puts you out of phase for the whole practice.
- Inhale through the left. Slow and quiet. Four counts is a reasonable starting length.
- Close the left, open the right, exhale. Ring finger closes as the thumb lifts. Aim for the exhale to be at least as long as the inhale.
- Inhale through the right, then close it and exhale through the left. That completes one round — two breaths, four phases, ending on the side you started.
- Do five to ten rounds. At a four-count that is roughly three to six minutes. Always finish on an exhale through the left.
The counting is the part that drifts. Most people speed up as they relax and let the exhale shorten, which quietly removes the feature that does the work. A pacer set to a slow even rhythm solves that — you follow its timing and do the switching yourself.
What the Evidence Actually Shows
This technique has been studied a great deal, mostly in small trials, and the pattern in the results is unusual: the effects it is rarely marketed on hold up best, and the ones in every headline hold up worst.
| Claim | Verdict | What the Research Actually Says |
|---|---|---|
| It lowers blood pressure | Supported | A meta-analysis of six randomized controlled trials with 525 participants found systolic pressure 7.16 mmHg lower and diastolic 5.16 mmHg lower than control. That is a clinically meaningful difference. Heterogeneity between the trials was extreme (I² of 93% and 87%), and the authors say plainly that the results need care in interpretation.1 A separate crossover study found systolic pressure fell after alternate nostril breathing but not after breath awareness or quiet sitting.2 |
| It shifts autonomic balance and improves cardiopulmonary measures | Supported | A systematic review of 44 randomized trials found consistent improvements in autonomic and cardiopulmonary measures — heart rate, blood pressure, pulmonary function. The same review notes that the technique has never been standardized across studies, which is why no meta-analysis of those outcomes was possible.3 |
| It reduces anxiety | Qualified | The 44-trial review found the evidence for anxiety and depression specifically to be minimal, which is striking for a technique sold almost entirely on calming.3 Breathwork in general does reduce anxiety by a small-to-medium margin,5 so the reasonable position is that it probably helps because it is slow breathing, not because it is nostril-specific. |
| Each nostril activates the opposite brain hemisphere | Not Shown | Sixty-four-channel EEG in 30 participants found that left-nostril breathing raised posterior EEG power and right-nostril breathing produced more anterior activation — but both hemispheres responded together. The authors state the pattern does not correspond to the classical model in which one nostril drives the opposite hemisphere.4 |
| It sharpens attention and cognitive performance | Not Shown | In the crossover study most often cited for the attention benefit, vigilance test times improved after alternate nostril breathing — and also after eighteen minutes of sitting quietly, with comparable error reduction across all conditions. An improvement that the control condition reproduces is not an effect of the technique.2 |
The Hemisphere Claim
Almost every article about this technique repeats some version of it: right nostril activates the left hemisphere, left nostril activates the right, alternating balances the two. It is a satisfying idea, it has a genuine research lineage going back to studies in the 1980s and 1990s, and it did not survive being measured properly.
A 2022 study put 30 people under 64-channel EEG and had them breathe through one nostril at a time.4 Breathing side did change the EEG — left-nostril breathing raised power in posterior regions, consistent with a calmer state; right-nostril breathing showed more anterior activation. But the changes appeared across both hemispheres together rather than crossing over. The authors say directly that this does not correspond to the classical model.
If the hemisphere mechanism were true, the alternation would be the active ingredient and the technique would be doing something no other breathing pattern can. Without it, what remains is slow, controlled, exhale-aware breathing with a physical ritual attached — which is a perfectly good thing to be, and is probably why it works. But it means the benefits are unlikely to be nostril-specific, and it removes the reason to prefer this over a simpler pattern you can do without your hands.
Why It Works
Slow breathing with a controlled exhale increases vagal influence on the heart, which shows up as higher heart rate variability and more pronounced respiratory sinus arrhythmia. Systematic review of the slow-breathing literature finds those shifts fairly consistently, alongside EEG changes and reports of calm — while noting the evidence is limited and the techniques studied are heterogeneous.6 Done at five to ten rounds, alternate nostril breathing is slow breathing, so it inherits all of that.
Two things may be specific to it. Closing one nostril raises airway resistance, which slows the breath whether or not you are counting — the technique enforces its own pacing in a way an open-mouthed pattern does not. And the hand position occupies attention. Neither is exotic, and neither requires the hemisphere story.
The blood pressure result deserves its own note, because it is the strongest thing here. A pooled 7 mmHg drop in systolic pressure is the sort of change that matters clinically.1 It also comes with an I² of 93%, meaning the six trials disagreed with each other enormously — some found much larger effects, some much smaller. A confidence interval that narrow across trials that heterogeneous is worth treating with suspicion. The finding is real and the precision is overstated.
When Something Else Is the Better Choice
- Your hands are not free. Driving, walking, sitting in a meeting, lying in the dark. This is the only technique here that needs a hand on your face, and that rules out most of the moments people actually want a breathing exercise.
- You are congested. A blocked nostril turns the practice into strained effort against resistance, which is the opposite of the point. Wait until it clears.
- You want the largest measured HRV response. Breathing at six a minute is the pattern with the most direct support for that, and it needs no hands. The coherent breathing pacer runs it.
- You want the fastest drop in arousal. A physiological sigh takes one breath. Nadi shodhana takes five rounds before anything settles.
What it has going for it is the ritual. The hand position, the counting, the alternation — that is a structure that occupies a wandering mind, and for a daily seated practice at a fixed time it is more engaging than watching a dot move. If you already have a yoga or meditation practice this fits into it naturally, and that matters more than a marginal difference in measured outcomes.
Variations Worth Knowing
| Variation | What changes | Where it stands |
|---|---|---|
| Nadi shodhana | The standard alternating pattern | The version nearly all the research used |
| With retention (kumbhaka) | A hold after the inhale, often 4-16-8 | Traditional, and the version to skip if the holds make you lightheaded |
| Right nostril only (surya bhedana) | In through the right every time | Taught as activating. The EEG work found more anterior activation, but not the hemisphere effect claimed for it |
| Left nostril only (chandra bhedana) | In through the left every time | Taught as calming. This one has the most support of the three — left-nostril breathing raised posterior EEG power, consistent with a calmer state4 |
Safety and Who Should Skip It
The 44-trial review reported no adverse effects or intolerance across any of its included studies,3 which makes this one of the lower-risk techniques on the site — as long as you leave the breath retention out.
Skip it entirely while congested, or with a deviated septum or recent nasal surgery. Add the retention only after the basic pattern is comfortable, and not at all if you are pregnant, or if you have a cardiovascular condition, uncontrolled blood pressure, epilepsy or a seizure history, glaucoma, or panic disorder. If you are taking blood pressure medication, the effect measured here is large enough to be worth mentioning to whoever prescribes it. Lightheadedness means stop and shorten the counts.
Building the Habit
The trials that found blood pressure effects mostly ran for weeks, not one session — this is a practice rather than a rescue tool, and that is the honest framing for it. Ten to fifteen minutes daily is the range most of the research used. The single-session effects are real but modest, and if you want something for an acute moment there are faster options with fewer requirements.
Because it needs both a seat and a free hand, it works best anchored to something you already sit down for. After you sit to meditate, before you get out of the car, first thing at your desk. What it will not survive is being scheduled for a moment when your hands are busy.
Common Questions
Does it really balance the brain hemispheres?
No. That is the claim most repeated about this technique and the one that has been tested and failed. A 64-channel EEG study found breathing side does change brain activity, but across both hemispheres together rather than crossing over — the authors say directly that it does not match the classical model. The technique still works; it works because it is slow breathing.
Which nostril should I start with?
Tradition says start by exhaling through the left and finish there too. There is no evidence the starting side changes the outcome. What does matter is starting on an exhale rather than an inhale, which keeps the rounds in phase.
Can I do it if my nose is blocked?
Not usefully. Closing one nostril when the other is already congested turns the exercise into effortful straining, which raises arousal rather than lowering it. Use a pattern that does not need your nose until it clears.
Is it safe with high blood pressure?
The blood pressure effect is the best-evidenced thing about this technique, which cuts both ways — an intervention large enough to matter is large enough to be worth mentioning to whoever manages your medication. Leave out the breath retention, which is the part that is not recommended with uncontrolled hypertension.
Is there a timer for this on the site?
No, and there will not be a full one. The technique needs a hand on your face to switch nostrils, which no timer can do for you. What a pacer can do is run the rhythm while you handle the switching — set the coherent breathing pacer to an even count and follow it.
How is this different from anulom vilom?
In practice the names are used interchangeably, and the research does not distinguish them consistently. Where teachers do separate them, nadi shodhana includes breath retention and anulom vilom does not. That distinction matters more for safety than for effect — the version without retention is the one to start with either way.
The Short Answer
Alternate nostril breathing has the strongest blood pressure evidence of any technique on this site, and the weakest support for the two things it is usually sold on. The hemisphere-balancing story has been measured and does not hold. The attention benefit was matched by sitting quietly in the study most often cited for it. What remains is a slow, structured, hands-on breathing practice with a real cardiovascular effect and a ritual that some people find much easier to stick with than watching a timer. That is a good reason to do it. It is a different reason from the one on the packet.
No timer can switch nostrils for you, so there is not one for this technique. Run an even slow rhythm and do the switching yourself.
- Nam, T. G., Jeong, H., Kim, K. H., and Jang, I. (2024). Effectiveness of alternative nostril breathing on blood pressure: a systematic review and meta-analysis of randomized controlled trials. Complementary Medicine Research, 31(5), 449–460. doi:10.1159/000539707
- Telles, S., Verma, S., Sharma, S. K., et al. (2017). Alternate-nostril yoga breathing reduced blood pressure while increasing performance in a vigilance test. Medical Science Monitor Basic Research, 23, 392–398. doi:10.12659/MSMBR.906502 — 15 healthy male volunteers, crossover design.
- Ghiya, S. (2017). Alternate nostril breathing: a systematic review of clinical trials. International Journal of Research in Medical Sciences, 5(8), 3273–3286. doi:10.18203/2320-6012.ijrms20173523
- Niazi, I. K., Navid, M. S., Bartley, J., et al. (2022). EEG signatures change during unilateral Yogi nasal breathing. Scientific Reports, 12, 520. doi:10.1038/s41598-021-04461-8
- Fincham, G. W., Strauss, C., Montero-Marin, J., and Cavanagh, K. (2023). Effect of breathwork on stress and mental health: a meta-analysis of randomised-controlled trials. Scientific Reports, 13, 432. doi:10.1038/s41598-022-27247-y
- Zaccaro, A., Piarulli, A., Laurino, M., et al. (2018). How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 12, 353. doi:10.3389/fnhum.2018.00353
Jay Newmark is a health writer with a background in kinesiology and seven years covering sleep, stress, and performance science for digital health and fitness publications. He writes about breathwork from a science-first perspective.