Category: Prevention and triggers

A keto headache comes from salt and water loss. When you cut carbs, insulin falls and your kidneys let go of sodium and water. The fix is more salt (2 to 3 grams of sodium a day), potassium from vegetables, and enough fluid. It usually starts on day two or three and fades within days.

Here is the part most keto advice gets wrong. The pain is not your brain running out of sugar. It is a plumbing change that starts in the kidney. Treat it as a salt problem, not a bread problem, and it usually settles on its own.

Why does a low-carb diet give me a headache?

Insulin does more than move sugar. It also tells your kidneys to hold on to salt. Cut the carbs and insulin drops within days. Your kidneys then release sodium, and water follows the sodium out. Your blood volume shrinks a little. Your blood pressure can dip. Your head feels that change as a dull, pounding ache.

The 2026 guideline from the Society of Metabolic Health Practitioners names this salt and water loss as the main driver of start-up symptoms. Its list starts with headache. Then come fatigue, light-headedness, poor focus, mood changes, cravings, muscle cramps and constipation.

There is a third driver, and it sits on the grocery shelf. Most of the salt in the standard American diet comes in packages and restaurant food. Quit chips, bread and drive-through meals on Monday, and your salt intake drops the same week your kidneys start dumping it. The food industry loaded your old diet with salt. When you leave that diet, you have to add salt back on purpose.

How long does a keto headache last?

The guideline says start-up symptoms begin within 2 to 3 days. Most last a few days. Some last 2 to 4 weeks. That is why day two or three often feels like the hardest day of keto. It does not mean the plan is failing. It means your insulin is coming down.

A headache that keeps going past a month, or gets worse each week, does not fit the start-up pattern. Get it checked.

How do you get rid of a keto headache?

Put back what the kidneys let go. The guideline gives plain numbers.

1. Sodium: 2 to 3 grams a day. That is 5 to 7 grams of salt, about one teaspoon. Salt your food freely, or sip salted bone broth.
2. Potassium: 3 to 4 grams a day, from food. Spinach and other leafy greens, tomatoes, cucumbers, zucchini and eggplant all count. A “light salt” that mixes potassium and sodium also helps.
3. Fluid, with the salt. The guideline calls water and sodium the key to the first weeks. Its fluid floor is at least 2 liters a day. Plain water alone will not replace the salt you lost.
4. Magnesium if cramps come along. The dose is 200 to 400 mg of elemental magnesium a day. Magnesium glycinate is well absorbed and easy on the gut. Skip it if you have kidney disease, are pregnant, or have a nerve and muscle disease. A spoon of pickle juice or yellow mustard is also on the list.
5. Enough food. The guideline notes that eating enough in this phase may ease symptoms. Low-carb is not a hunger diet. Protein comes first, about 25 to 30 grams per meal.

Store-bought electrolyte drinks may help too, the guideline says. Read the label first. Many are sugar drinks with a pinch of salt.

Who should not treat it alone?

Some headaches on low-carb are a medicine problem, not a salt problem. Blood pressure pills and water pills keep working while your body sheds salt on its own. Your pressure can drop too far. The warning signs the guideline names are light-headedness when you stand up and heavy fatigue. Diabetes drugs can push blood sugar too low. The first 2 to 3 days carry the greatest risk.

The guideline also lists drugs that can push sodium too low, and some are headache treatments. NSAIDs such as ibuprofen are on it, along with opioid pain medicines and several antidepressants used to prevent headaches, such as amitriptyline. Taking them while your kidneys shed salt can make the drop bigger.

So here is the one rule. Your doctor makes medication changes, not you. That goes double for insulin, sulfonylureas, SGLT2 inhibitors and blood pressure drugs. The guideline asks people on these drugs to check blood pressure at home every day. If you have diabetes, check blood sugar daily too, with some readings 1 to 2 hours after a meal. Bring the numbers to your visit.

Salt advice changes for some people. If you have heart failure, kidney disease or salt-sensitive high blood pressure, let your doctor set your salt amount before you add any.

When is a headache on keto not keto flu?

A start-up headache is dull, builds slowly and eases with salt. The ones below do not fit that pattern. Go to an emergency room for any of them.

• A headache that peaks within seconds to a minute.
• A headache with fever and a stiff neck.
• Weakness, numbness, confusion, trouble speaking or loss of vision.
• A headache after a blow to the head.
• A new or changed headache after age 50.

The full list is in headache red flags: when to go to the emergency room.

Can low-carb help migraines?

It may, and the research is still going on. The guideline lists migraine among the brain conditions where ketogenic diets are being studied. It notes that these brain uses may need deeper ketosis than weight loss does. It also names migraine as one condition whose medicines may need review as metabolic health improves.

Dr. Padda did not always think this way. For years he was a strict vegetarian who taught the low-fat rules. The physiology changed his mind, and he says so. Today he treats migraine as part of the whole metabolic picture, not a brain glitch on its own. On his plate, industrial seed oils come out and refined grains go. Real olive oil stays. Red meat and fish are welcome. Those are his positions. The guideline does not name seed oils.

One plain note about the guideline. It is an expert consensus, built from a panel vote and a broad but non-systematic review of studies. It is not a clinical trial. Its value here is practical: clear numbers for salt, fluid and medicine checks. Dr. Padda holds the society’s Metabolic Health Practitioner credential. He did not write or vote on this guideline.

What should I do if my head hurts on day three?

A keto headache is a side effect you can fix, not a verdict on the diet. Salt your food. Eat your greens. Drink with the salt, not instead of it. Keep your doctor in the loop on every pill you take. If the headache is severe, strange or will not quit, we see headache patients in St. Louis, usually the same day.

Questions about keto headaches

Should I quit low-carb if I get a headache?

Usually not. Start-up headaches come from salt and water loss and tend to pass within days to a few weeks. Add salt, potassium-rich vegetables and fluid first. If the headache is sudden, severe or comes with other symptoms, see headache red flags.

Do electrolyte drinks help a keto headache?

They can. The guideline says store-bought electrolyte solutions may be useful in the start-up weeks. Check the label for sugar. Salted bone broth does the same job with no sugar at all.

Why do I still get headaches on keto after two months?

The start-up phase usually ends within 2 to 4 weeks. A headache that returns months later has another cause. It may be a medicine that now needs a new dose, or a headache disorder of its own. That needs an exam. See migraine or tension-type headache.

Sources

1. Rice SM, Buchanan LA, Calkins MW, Cucuzzella MT, Cywes R, Devine PL, Kalamian M, Kalayjian T, Reynolds DB, Westman EC. A Delphi consensus-based guideline for the implementation of therapeutic carbohydrate reduction in metabolic disorders. Journal of Metabolic Health. 2026;9(1):a152. doi:10.4102/jmh.v9i1.152

Magnesium, riboflavin and coenzyme Q10 have the longest track record in migraine prevention among supplements. Vitamin D is a different case. It is worth measuring and worth correcting if low. It is not worth taking blind.

Graded honestly, because supplement advice in headache is usually handed out as one flat list. Nothing says which items carry weight. That is why people give up on all of them at once.

Does magnesium help migraines?

The clearest evidence is in migraine with aura and in people who are truly deficient. It is inexpensive, widely available and generally well tolerated. For most people, the effect that limits the dose is loose stools. That varies a lot by salt form.

It is also used intravenously (by IV) as part of acute treatment for some attacks — see IV migraine therapy. That is a different use from a daily supplement by mouth.

Does riboflavin (vitamin B2) help migraines?

It has long been used in migraine prevention, at doses well above what food provides. It is cheap and safe. The main visible effect is bright yellow urine, which is harmless. Like the others it takes weeks to months. It is judged against a diary rather than an impression.

Does CoQ10 help migraines?

Also used for prevention, on similar evidence and a similar timescale. Cost is the main practical concern.

Does vitamin D help migraines?

Low vitamin D is consistently associated with migraine across observational studies. Supplement trials paint a weaker and less consistent picture. Several show a drop in headache frequency, and others show little. The clearest benefit tends to appear in people who were truly deficient to begin with.

The sensible reading is to measure it rather than guess, and to correct a real deficiency. That is worth doing for reasons beyond headache anyway. Supplementing an already-normal level in the hope of a headache benefit is not supported by the evidence.

Note the line being drawn here. An association between low levels and a condition does not establish that raising the level treats the condition. That is a common and expensive mistake in supplement marketing.

How do I know if a migraine supplement is working?

• One at a time. Starting three together means learning nothing about any of them.
• Give it eight to twelve weeks. None of these acts quickly.
• Count on paper. Headache days per month before and after, not a general sense of improvement.
• Expect a reduction, not an end. A meaningful result is fewer days, not zero.

The thing that outweighs all of them

Are you treating headache on more than about ten days a month? Then that is the main thing driving your frequency, and no supplement will outrun it. Address medication-overuse headache first. Then judge whether anything else is working.

Aerobic exercise, by the way, has better trial evidence in migraine prevention than any supplement on this page. Regular and moderate beats occasional and hard. See headache prevention.

Common questions

Which magnesium should I take?

Salt form mainly affects how well you tolerate it, not how well it works. The citrate and glycinate forms are usually better tolerated than oxide. Start low, since loose stools are the common effect that limits the dose. See headache prevention.

Should I just take a high dose of vitamin D to be safe?

No. Vitamin D is fat-soluble, and too much is not harmless. Measure the level, correct a real deficiency, and recheck — see headache prevention.

Can I take these with my prescribed migraine medication?

Usually. But tell us what you are taking so we can check interactions and avoid doubling up on ingredients. Bring the actual bottles — contact us.

How will I know if it’s working or just a good month?

You will not, without a written count. Migraine frequency shifts month to month for reasons unrelated to treatment. That is exactly why a diary matters more here than gut feeling. See headache prevention.

Can low vitamin D cause migraines?

Low vitamin D is consistently associated with migraine in observational studies. But an association does not prove that raising the level treats migraine. Supplement trials are mixed. The clearest benefit shows in people who were truly deficient. Measure your level, correct a real deficiency, and recheck rather than taking vitamin D blind. See headache prevention.

What is the best supplement for migraine prevention?

Magnesium, riboflavin and coenzyme Q10 have the longest track record among supplements. Each takes weeks to months. Two things outrank all of them. The first is stopping medication overuse if you treat headache on more than about ten days a month. The second is regular moderate aerobic exercise, which has better trial evidence in migraine prevention than any supplement. See medication-overuse headache.

Does riboflavin have side effects?

Riboflavin is cheap and safe at the doses used for migraine prevention. The main visible effect is bright yellow urine, which is harmless. Like the other supplements it acts slowly. Give it eight to twelve weeks and judge it against a written headache diary rather than an impression. See chronic vs episodic migraine.

Can magnesium be given by IV for a migraine attack?

Yes. Magnesium is used intravenously as part of acute treatment for some attacks, as one piece of IV migraine therapy. That is a different use from a daily supplement by mouth, which works slowly as prevention. The IV treatment is aimed at an attack that is already underway. See when a migraine will not break.

Sources

1. Chiu HY, Yeh TH, Huang YC, et al. Effects of Intravenous and Oral Magnesium on Reducing Migraine: A Meta-analysis of Randomized Controlled Trials. Pain physician, 2016. PMID 26752497. pubmed.ncbi.nlm.nih.gov
2. Schoenen J, Jacquy J, Lenaerts M. Effectiveness of high-dose riboflavin in migraine prophylaxis. A randomized controlled trial. Neurology, 1998. PMID 9484373. pubmed.ncbi.nlm.nih.gov
3. Sándor PS, Di Clemente L, Coppola G, et al. Efficacy of coenzyme Q10 in migraine prophylaxis: a randomized controlled trial. Neurology, 2005. PMID 15728298. pubmed.ncbi.nlm.nih.gov
4. Hu C, Fan Y, Wu S, et al. Vitamin D supplementation for the treatment of migraine: A meta-analysis of randomized controlled studies. The American journal of emergency medicine, 2021. PMID 34879503. pubmed.ncbi.nlm.nih.gov

If you change one thing about your sleep for migraine, make it the wake time, and hold it on weekends.

The relationship runs both ways: poor sleep provokes attacks, and attacks wreck sleep. But the direction that matters for prevention is the first one, and the lever is timing rather than quantity.

Why do I get migraines after sleeping in?

Migraine is sensitive to change. A shifted sleep schedule moves the body clock. The disruption is what provokes the attack, not the extra sleep itself. This is why so many people describe reliable Saturday-morning migraines. They assume the cause must be something they ate or drank on Friday.

The same mechanism explains attacks after a night shift and after travel across time zones. It also explains attacks after catching up on sleep following a bad week. The common factor is an irregular schedule.

Two things worth screening for rather than managing at home

Can sleep apnea cause morning headaches?

Morning headache is a classic sign. Obstructive sleep apnea (OSA) is very commonly missed, particularly in people who do not fit the expected picture. Do you wake with headache most days, snore, or feel unrefreshed after enough hours? Then this is worth investigating rather than treating as a headache problem.

Why does my headache wake me up at the same time every night?

Cluster headache has a striking tendency to strike from sleep at the same hour, often within a couple of hours of falling asleep. That is a diagnostic clue rather than a sleep disorder. If your headaches wake you at a predictable time and are over within three hours, read migraine or cluster headache.

Can insomnia make migraines worse?

Insomnia is an established risk factor for episodic migraine turning chronic. So sleep is one of the contributors you can change. It is worth taking seriously, alongside medication overuse. It is not generic advice tacked onto the end of a visit.

Cognitive behavioral therapy for insomnia has better evidence than sleeping pills, and it does not carry the rebound risk that sedatives do.

How can I sleep better to prevent migraines?

• Fix the wake time first. Same time every day including weekends. Bedtime can drift; the wake time should not.
• Do not chase lost sleep. Sleeping in late after a bad night costs more than it recovers, for a migraine brain.
• Keep caffeine timing consistent, not just limited. A late or missed daily coffee causes a withdrawal headache of its own.
• Treat the snoring question seriously if morning headache is your pattern.
• Give it six weeks and judge against a headache diary rather than an impression.

None of this outruns a rebound cycle. If you are treating headache on more than about ten days a month, address that first — see headache prevention.

Common questions

Is it bad to sleep off a migraine?

No. Sleep truly stops attacks for many people and is a reasonable acute strategy. The regular-schedule advice is about prevention between attacks. It is not about refusing to sleep during one. See migraine treatment.

I work night shifts. What can I do?

Consistency is still the goal even when the schedule is unusual: the same sleep window on work days, and as little rotation as your employer allows. Rotating shifts are harder on migraine than permanent nights. See headache prevention.

Should I take something to help me sleep?

Be careful. Some sedatives and many combination painkillers containing them feed a rebound cycle. CBT for insomnia has better evidence and no rebound risk — see medication-overuse headache.

How long before better sleep shows up in my headache count?

Give it about six weeks and judge against a written diary. Sleep changes act slowly and are easy to abandon before they have had a chance. See headache prevention.

Can lack of sleep cause migraines?

Yes. Poor sleep provokes attacks, and attacks in turn wreck sleep. For prevention, the timing of sleep matters more than the amount. Attacks after a night shift, after travel across time zones, or after catching up on sleep following a bad week all share one cause: an irregular schedule that moves the body clock. See migraine treatment.

Can too much sleep cause a migraine?

The extra sleep itself is not the trigger. The shift in schedule is. Sleeping in on the weekend moves the body clock, and that disruption is what provokes the attack, which is why so many people get reliable Saturday-morning migraines. Keeping the same wake time every day, weekends included, removes that trigger. See headache prevention.

Why do I wake up with a headache every morning?

Morning headache is a classic sign of obstructive sleep apnea. Sleep apnea is very often missed, particularly in people who do not fit the expected picture. Do you wake with a headache most days, snore, or feel unrefreshed after enough hours in bed? Then get it investigated rather than treating it as a headache problem. See when a headache needs a scan.

Sources

1. Stanyer EC, Creeney H, Nesbitt AD, et al. Subjective Sleep Quality and Sleep Architecture in Patients With Migraine: A Meta-analysis. Neurology, 2021. PMID 34551985. pubmed.ncbi.nlm.nih.gov
2. Daou M, Vgontzas A. Sleep Symptoms in Migraine. Current neurology and neuroscience reports, 2024. PMID 38864968. pubmed.ncbi.nlm.nih.gov

If you are treating headache on more than about ten days a month, that alone may be driving your headache frequency. This pattern is called medication-overuse (rebound) headache. No preventive will outrun it until it is addressed.

This is the single most important idea on this site, and the most commonly missed. People arrive sure their disease has worsened. Often a large part of what has worsened is a cycle the medicine cabinet is keeping alive.

The thresholds are specific

Medication-overuse headache is a formal diagnosis with defined criteria. Under ICHD-3 it requires headache on 15 or more days a month in someone who already has a headache disorder. It also requires regular overuse for more than three months of a drug taken for acute headache treatment.¹

The overuse threshold depends on the drug:

• Simple analgesics — acetaminophen, aspirin, other NSAIDs: 15 or more days a month²
• Triptans: 10 or more days a month³
• Ergotamines, opioids, and combination analgesics: 10 or more days a month¹

Note how much lower the bar is for combination products and opioids. A combination painkiller taken twice a week for three months meets the criterion. Most people are truly surprised by that.

Why it happens

Repeated acute dosing appears to sensitize the trigeminal pain system and lower the threshold for the next attack. The practical result is a loop that feeds itself: more attacks, so more treatment, so more attacks. The drug that reliably stopped an attack a year ago now gives a few hours of relief. Then the headache returns, which prompts the next dose.

The pattern people describe is distinct. The headache is there on waking. It responds partly and briefly. Skipping a dose makes it worse within hours. That last feature — a headache that punishes you for not taking something — is the clearest signal.

Opioids are the worst offenders, and this is why

Opioids are a poor choice for migraine on their own terms. They do not address the mechanism. They worsen the nausea. They interact badly with the antiemetics (anti-nausea drugs) that do help. But the larger problem is the 10-day threshold. Opioids cross into medication overuse at that low bar. They are also strongly associated with progression from episodic to chronic headache.

That is a clinical-quality argument about primary headache specifically. It does not say opioids have no place in pain medicine. They remain necessary in several conditions this practice treats, including head and neck cancer pain.

Unwinding it

The treatment is withdrawal of the overused drug. The hard part is that withdrawal makes the headache worse before it makes it better. That is the reason people fail on their own. They read the worsening as proof the medication was necessary.

The window is usually days to a couple of weeks. What makes it survivable is covering that period with something that does not feed the cycle. Intravenous therapy can break the acute headache during withdrawal without adding to the overuse. A nerve block can do the same. Its effect outlasts the injection by weeks.

Once through it, many people find their underlying headache frequency is substantially lower than it appeared. Sometimes it is low enough that they no longer meet criteria for chronic migraine at all.

Do this before starting a preventive

Are you heading toward Botox or another preventive because you are at 15 or more headache days a month? Then the rebound question comes first. Starting an expensive preventive to fight a problem your medicine cabinet is creating is a poor use of both.

Bring a month of honest counting. Not an estimate — a calendar with every dose of everything. Include what you bought over the counter and what you took for something else. See headache prevention for what comes after.

Common questions

Does this mean I should stop my medication today?

Not without a plan. Abrupt withdrawal from some drugs is unsafe. And the rebound period is much harder alone. Bring your list and we will work out the order — contact us.

I only take over-the-counter painkillers. Can that really do it?

Yes. Simple analgesics (basic painkillers) cross the threshold at 15 days a month. Combination products — including many over-the-counter ones with added caffeine — cross it at 10. Over-the-counter does not mean free of consequences.

How long until it improves after stopping?

The withdrawal period is usually days to a couple of weeks. Improvement continues over the following weeks to months. We cover that window rather than asking you to endure it — see IV migraine therapy.

Does caffeine count?

Daily caffeine builds dependence, and a missed or late dose can cause a withdrawal headache. It is not counted the same way as an acute headache drug. But if you drink it daily, what matters is keeping the timing consistent. See headache prevention.

Will I need this treated before Botox?

Usually yes. Many people who meet the 15-day threshold are in a rebound cycle. Treating that first sometimes drops the frequency below the chronic threshold on its own. See Botox for chronic migraine.

Sources

1. Headache Classification Committee of the International Headache Society. ICHD-3, 8.2 Medication-overuse headache. ichd-3.org
2. Headache Classification Committee of the International Headache Society. ICHD-3, 8.2.3 Simple analgesic-overuse headache. ichd-3.org
3. Headache Classification Committee of the International Headache Society. ICHD-3, 8.2.2 Triptan-overuse headache. ichd-3.org