Can Acidic Foods Affect Stimulant Medications for ADHD?

can too much acid or too little affect how stimulants work photo of citrus fruits and pills


Can foods—particularly those containing citric acid—affect how well you absorb stimulants, such as Ritalin, Adderall, and Vyvanse?

I get that question a lot. So, let’s delve into answering it.

In a word, yes. Yes, food can interfere!   Most specifically, an overly acid or alkaline system (ph) can affect some stimulants’ effectiveness.

For example, citric acid and antacids can mean the difference between a stimulant working—or not.  This bears thinking about, because many Americans consume an extremely acid diet (e.g. soda, meat, cheese, chocolate, pasta, beer, wine, most grains, etc.).

But the cautions don’t stop with Ph. Even calcium or ammonium chloride, a food additive to bread and certain types of licorice can reduce stimulant effectiveness.

Grapefruit juice can also create problematic interactions with stimulants and many other medications.  Chemicals in grapefruit can interfere with the enzymes that break down (metabolize) the medication in your digestive system. That means the medication may stay in your body for too short or too long a time. When a medication breaks down too quickly, it has insufficient time to work. A medication that stays in the body too long may build up to potentially dangerous levels.

Unfortunately, many prescribing physicians remain unaware of these interfering factors.

By the way, did you find this page while searching for “hacks” to abuse stimulants? You’ll be disappointed. For example, maybe you read somewhere that downing an orange juice chaser with your Adderall pill will boost the effect? I cannot possibly say.

Ph Spectrum: Acidic to Alkaline

Please keep in mind:  There are many other explanations to explain why a stimulant medication fails—or ceases to work—for an individual. They include genetic and physiologic.

Right now, though, let’s view this issue primarily through the narrow lens of ph (alkalinity and acidity).  Merriam-Webster defines ph this way:

a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution; also: the condition represented by a pH number.

Citric Acid and Stimulant Absorption

Many years ago, I learned that citric acid can reduce the stimulant’s absorption—because it changes the ph of the gut. So, if someone complained to me of reduced effect from the medication,  I would ask about any new habits around citric acid consumption. This might include:

  • Drinking orange juice
  • Eating certain fruits
  • Taking a vitamin C supplement
  • Eating some other food product containing citric acid as a preservative.  (Examples of the latter include soft drinks, fruit-flavor candies, and even some cooking stock/bouillon.)

The general rule, I’d heard: Do not consume citric acid an hour before or after taking the stimulant. I’ve heard the same of a high-fat meal—to avoid it around the time you take stimulant medication, as it can reduce absorption.

This webpage (Citric Acid in Foods) contains a list of foods that contain citric acid naturally or to which it is added. The list is bigger than you might think, including berries, preserves and jams, and mayonnaise that is made with lemon juice. With children, think gummy bears, “fruit” chews, and all the other candy masquerading as fruit items.

Acidic Foods Affect Stimulants

Then again, I’d also heard that this acid/absorption issue applies more to the immediate-release medications. It’s less of a risk with the novel delivery systems for extended-release stimulants such as Vyvanse and Concerta.

One rumor is that citric acid actually improves absorption. As it turns out, that’s not the case.

Moreover, many middle-aged folks with late-diagnosis ADHD—their guts suffering from years of scattershot eating habits and stress—are also taking antacids.  Can that affect stimulant effectiveness, too?  You bet.

Acidic Foods Affect Stimulants

Let’s start solving this puzzle by examining medication label inserts, textbooks, and published literature. Read on.

Paper Inserts Shed Light

I checked the label insert for various stimulants. They offered some information.

Basically, yes, the gut ph (alkalinity/acidity) can reduce absorption. But it seems to vary by delivery method. That is, the way the medication travels from the pill (or other) to the bloodstream. For example, Adderall, Concerta, Vyvanse, and Daytrana (the patch) are all delivered via different mechanisms.

To read the product insert for each medication, click on the hyperlinked name.


  • Acidifying agents: 
    • Gastrointestinal acidifying agents (guanethidine, reserpine, glutamic acid HCl, ascorbic acid, fruit juices, etc.) lower absorption of amphetamines.
    • Urinary acidifying agent (ammonium chloride, sodium acid phosphate, etc.) increase the concentration of the ionized species of the amphetamine molecule, thereby increasing urinary excretion.
    • Both groups of agents lower blood levels and efficacy of amphetamines.
  • Alkalinizing agents
    • Gastrointestinal alkalinizing agents (sodium bicarbonate, etc.) increase the absorption of amphetamines. Coadministration of Adderall and gastrointestinal alkalizing agents, such as antacids, should be avoided.
    • Urinary alkalinizing agents (acetazolamide, some thiazides) increase the concentration of the non-ionized species of the amphetamine molecule, thereby decreasing urinary excretion.
    • Both groups of agents increase blood levels and therefore potentiate the actions of amphetamines.

Summary: A system that is too alkaline or acid will reduce medication effectiveness.

Adderall XR:

  • Alkalinizing agents (GI antacids, including sodium bicarbonate, and urinary): These agents increase blood levels of amphetamine. (7.1)
  • Acidifying agents (GI and urinary): These agents reduce blood levels of amphetamine. (7.2) One of these acidifying agents is ammonium chloride, also known as sal ammoniac; Wikipedia has this to say about ammonium chloride:

In several countries, ammonium chloride, known as sal ammoniac, is used as a food additive under the E number E510, commonly as a yeast nutrient in breadmaking. It is a feed supplement for cattle and an ingredient in nutritive media for yeasts and many microorganisms.

Ammonium chloride is used to spice up dark sweets called salty licorice (very popular in Nordic countries, especially in Finland), in baking to give cookies a very crisp texture, and in the vodka Salmiakki Koskenkorva for flavouring. In India and Pakistan, it is called “Noshader” and is used to improve the crispness of snacks such as samosas andjalebi


  • Urinary acidifying agents may reduce blood levels of amphetamine. (7.1)
  • Urinary alkalinizing agents may increase blood levels of amphetamine. (7.2)


Acidifying agents: Gastrointestinal acidifying agents (guanethidine, reserpine, glutamic acid HCl, ascorbic acid, fruit juices, etc.) lower absorption of amphetamines.

  • Urinary acidifying agents (ammonium chloride, sodium acid phosphate, etc.) increase the concentration of the ionized species of the amphetamine molecule, thereby increasing urinary excretion.
  • Both groups of agents lower blood levels and efficacy of amphetamines.


[No ph interactions listed, perhaps because Daytrana is a methylphenidate patch worn on the skin and is not absorbed through the gut.]


  • In patients, there were no differences in either the pharmacokinetics or the pharmacodynamic performance of CONCERTA® when administered after a high fat breakfast. There is no evidence of dose dumping in the presence or absence of food.

[The label makes no mention of ph interactions, perhaps due to Concerta’s  novel delivery system.]

Ritalin LA:

  • Especially tell your doctor if you or your child takes stomach acid medicines.

Focalin XR:

  • Antacids or acid suppressants could alter the release of Focalin XR
  • The effects of gastrointestinal pH alterations on the absorption of dexmethylphenidate from Focalin XR have not been
    studied. Since the modified release characteristics of Focalin XR are pH dependent, the coadministration of antacids or
    acid suppressants could alter the release of dexmethylphenidate.

The Literature Tells Us This

Next, I checked the literature (not an exhaustive search at this point) and found this information:

In an in vitro study, the pH-solubility profile of LDX was determined in buffered aqueous solutions using an assay specific for LDX.

The environmental pH did not affect the solubility profile of LDX within the biological pH range (pH, 1–8), suggesting that gastric pH variation does not affect the absorption of LDX.

Due to the effect pH has on absorption, amphetamine also interacts with gastric acid reducers such as proton pump inhibitors and H2 antihistamines, which increase gastrointestinal pH (i.e., make it less acidic).

grapefruit and medication

Grapefruit’s Particular Challenges

Now consider a very particular type of citrus: grapefruit. Beyond any considerations about acid and Ph, grapefruit—both the fruit and the juice—can create adverse outcomes when taken with certain medications, including some stimulants.   What’s the culprit here? It seems to be flavonoids called furanocoumarins.

Wikipedia has a very clear entry on this topic, excerpted here:

These active materials inhibit a key enzyme (cytochrome P450 isoform CYP3A4) which is responsible (among other activities) for drug metabolism. The effect happens in two ways.

One is that grapefruit can block the hepatic CYP3A4 thereby affecting the medication metabolism. If the drug is not metabolized, then the level of the drug in the blood can become too high, leading to an adverse effect.

On the other hand, if the medication is provided as a pro-drug [Gina notes: Vyvanse is a pro-drug], compromising its metabolism may prevent the drug from being created, thereby reducing its therapeutic effect.

The other effect is that grapefruit can block the enterocyte CYP3A4 thereby affecting the medication absorption in the intestine. Absorbing the medication to a lesser extent means it may not reach a therapeutic level. Therefore, its effect may be compromised.

In other words, grapefruit juice can be a problem in two big ways:

1. Create a toxic too-high dose of the medication
2. Reduce the medication’s therapeutic effect.

Acidic Foods Affect Stimulants

The list of grapefruit’s potential drug interactions is long. Here is a sampling, again from the Wikipedia entry on Grapefruit-drug interactions:

  • Benzodiazepines
  • All the stimulant medications
  • SSRI antidepressants
  • Statins
  • Anti-Erectile Dysfunction medications
  • Acetaminophen

Cytochrome P450

For more information on cytochrome P450, check this post from the series I wrote with my molecular-biologist husband:  Part 4: Gene-Testing to Inform ADHD Drug Therapy.

The Bottom Line

It should be clear, from this brief examination, that ph can be a factor in stimulant efficacy.  Grapefruit juice has its own particular effect on the absorption of stimulants and other medications. We also touched briefly upon the role of calcium, fat, and food additives such as ammonium chloride.

This is a reminder that stimulants do not act in a vacuum. They act in a highly individual human body.  To be most effective, the stimulants require physiological support, including but not limited to:

  • Adequate sleep: Stimulants cannot compensate for sleep deprivation
  • Good nutrition:  All medication targeting neurochemicals need “helpers”—B vitamins, potassium, magnesium, and other vitamins and minerals that help to fuel neural transmission (“moving messages around”).
  • Adequate protein:  Not “high protein” but rather adequate—because proteins are composed of amino acids. Amino acids are the building blocks of neurotransmitters such as dopamine, serotonin, and the like.

What’s Your Experience?

I’d love to hear your experiences on this topic. For example:

  • Have you found that acidic foods affect your stimulant’s effectiveness?
  • Have you noticed that taking an antacid creates problems with your stimulant being effective?
  • Did your physician ever mention these factors?  If so, what information did you receive?
  • If you have particular knowledge in this area, please write a comment and I will incorporate it into this post for future readers to benefit. Thanks.

—Gina Pera

229 thoughts on “Can Acidic Foods Affect Stimulant Medications for ADHD?”

  1. Back in the old days, when I was 35-40 or so, I discovered that my Gobstopper habit was affecting my Vyvanse. Now that I’m 55, nothing works well enough to make observations like that. I can no longer access Vyvanse because insurance doesn’t work, manufacturer coupon doesn’t work. So I’m on generic Adderall. The current generic is better than the previous, but in general it’s hard to fight the fog. I don’t feel I’m In a good enough treatment place to be able to assess citric acid impact, because I must have other factors going on too… menopause, thyroid, etc… I am curious about the vitamin water I’m addictive to from the fountain at QT. I get it to stay off soda, but I suspect it’s a player. Regarding this: was given an instruction sheet with tips about diet and citric acid only once, probably 20 years ago and I wish I still had that sheet. I have since told friends, and even my new providers.

    1. Hi Jenn,

      “vitamin water”? Probably has citric acid.

      But yes, as perimenopause and menopause draws near and estrogen drops, it can affect cognition for many women, not just those who have ADHD. But for those who do, Patricia Quinn, MD, suggests looking into bioidentical hormones and a stimulant.

      Also, ADHD neurobiology can affect thyroid function.

      Also, Vyvanse might have a financial assistance program for you, beyond the coupons that work with insurance.

      This blog post is probably more detailed than that instruction sheet.

      good luck,

  2. Mystery solved then. My medication works great, except on Sundays. Guess what I have for breakfast on Sunday? Freshly squeezed orange juice.

    1. First off: where is the main comment part on the web page? I have to reply to someone else’s comment to comment.

      I never knew the amount of time for orange juice or vitamin c to interact with my Ritalin. I always thought it was 2 hours so I typically take my vitamin c before bed. Occasionally I’ll have strawberry lemonade but it’s at least an hour and a half after I take my meds.

    2. Hi Mindy,

      Scroll down past the comments and you’ll see the comment box.

      I think a software update changed the previous position — before the comments.


  3. Rebecca Nicholls


    Just going back to the acid reflux issue. Have you have a camera down your esophegus to check of any issues. A barrium is also suggested at the same time to cover all bases.

  4. I’m confused by exactly how the difference in ph affects me because it’s seems that anything I eat results in symptoms consistent with “dose dumping”. At least while I was taking Vyvanse in combination with Wellbutrin. Because of problems with this I have stopped taking both. I have just switched to Adderall XR in the hopes that it would be less sensitive to food. I was off both of them for a week before starting Adderall XR. So far it’s been a few days taking it so I still have to see it through but it seems effected by it less intensely but it still happens. But maybe it will be better in time. I really need to find a medication that works for me but I need to also be able to eat normally. In that past I partially dealt with this by trying to manipulate when I ate and to eat less but it never fixed the problem and its non sustainable. I’m not really sure how to deal with this and my doctor doesn’t have many ideas. But they are open to changes in to medications or taking another ones if I suggest them.

    There was a time where vyvanse and Wellbutrin worked really well but it would not last because of these problems and I can’t approach the doses that has been helpful in the past because the higher I go the more sensitive I seemed to become to food and too low made eating less of a problem but the medication was reduced to a level of efficacy much lower than what was helpful. Also no one talks about this and it needs more attention I’m glad to see what you’ve written about it:)

    1. Hi Roberto,

      It might be that ph has nothing to do with your reaction to Rx.

      This is complex…..dialing in ADHD medications while also developing new habits that support Executive Functions…..and getting enough sleep and eating well, etc.

      Lots of moving parts. I would not over-focus on the Ph issue until you’ve optimized other points.

      I’m curious why you dropped Vyvanse and Wellbutrin and moved to Adderall XR…..instead of just trying the Vyvanse?


    2. Dose dumping note

      Hi sorry I didn’t realize you responded so quickly and it won’t let me reply to your
      Comment so I’ll just reply to mine and hopefully It still shows you.

      You’re right It could not be the ph issue I could not be accounting for something else and it could be many things. All I know is that I had consistent problems eating that seemed to fit the the description of dose dumping. I’m not sure what exactly the problem with eating is but I’m not sure sure what to do at this point.

      As far as why I stopped taking vyvanse and Wellbutrin. I could not stay on therapeutic doses of Wellbutrin because it seemed to interact with the vyvanse and lowering it would help but eventually I got so low it didn’t make sense to take it all. I didn’t try vyvanse on its own for two reasons but I did consider it and it’s still option to go back to I guess. But basically while on vyvanse I had trouble eating foot because of the “dose dumping” like experience that I mentioned before. So I was hoping I could achieve the partial success from vyvanse all the time on adderall in the hopes that eating wasn’t as sensitive to me on it. I know adderall has a somewhat different mechanism of delivery and maybe it works better for me. Also adderall even xr version is supposed to start working more quickly where as vyvanse took roughly 3 hours for me to feel something significant. This was a pain to work around especially if say trying to make sure I have enough time to eat before hand and than wait for a little while then take it (one of the ways I tried to deal with this the eating problem. This lead to many hours before actually feeling any benefit. As a result delayed how long until I could function a much better level.

      If there is someway to recreate how I would sometimes feel on vyvanse and Wellbutrin all the time and eat normally unaffected. It would actually be life changing.

    3. It’s a puzzle, Roberto. But it’s best figured out if you change only one variable at a time.

      Yes, Wellbutrin and Vyvanse is not a good pairing for many people with ADHD. It can really ramp up anxiety.

      It truly might have been the Wellbutrin that was sending things in a negative direction.

      Or the Vyvanse!

      You won’t know until you try separately. This is why I am not a fan of prescribers starting with two (or more!) medications. You’ll never get a clear reading on what’s doing what!

      good luck,

  5. Anonymous Adderall User

    Now I’m confused about what I’m even supposed to eat. I don’t want to eat at all, this stuff makes it seem like I can’t eat anything. Can you give some real life examples?
    I wanted to start doing smoothie bowls again now that the weather is warming up, is that too acidic?
    Everything seems either too acidic, too sugary, or too fatty when I try to think of meals 🙁

    1. Hi Anonymous Adderall user,

      Now that’s a bit of “all or nothing” ADHD talking there…. :-). Aim for balance.

      Sorry but this is something you’ll have to figure out yourself. I can’t predict what is in your smoothie bowl. Maybe re-read the details I provided about Adderall. Test it and see. Does your Adderall not seem to work after consuming certain foods?

      As an aside, it’s generally better for glucose regulation to consumer fiber with fruit — that is, not pulverized fiber. It helps to slow sugar uptake.

      I hope this helps.

  6. There is far too little research on this topic and thank you for your work to summarize what we do know! Let me add my experience with magnesium supplements. If I have taken any amount of magnesium, any form of it, even just a regular adult multivitamin, within the previous 36 hours, it affects how I process IR adderall. I react with the exact same side effects as if I had taken a dose of adderall that is too high (significantly elevated heart rate, etc). However, foods containing magnesium, like bananas, do not cause those issues for me. This needs further research. Most studies assume that magnesium cannot affect absorption if it is taken several hours before. But for some people like me, it may have an affect for much longer. I would like to understand how and why my body reacts this way.

    1. Hi Martha,

      You’re welcome! thanks for your comment.

      It just might be that you are magnesium-deficient. Taking a supplement might mean that you can take a lower dose of your stimulant medication, because it will work more efficiently.

      When one is mag-defining, trying to address that with food can be difficult. The amount is much smaller.

      I hope this helps

  7. So I have GERD and I take pantoprazole. Since concomitant use of gastric ph modulators can change the release profile, shape of pharmacokinetic profile, and exposure to extended release medications like Adderall XR, I believe what is happening is what they refer to as “dose dumping” where the entire dose or a significant fraction thereof is being released too soon. I can’t go off of the PPIs, so I need to figure out what my best option is as far as an extended release medication which will stay in my system longer. I’ve tried Vyvanse, which gave me severe nausea (no other stimulant meds give me nausea so I’m not sure why it did). I’ve looked at Mydayis which contains 3 beads instead of 2 like Adderall XR. Mydayis is formulated to release some beads immediately, some at ph 5.5, and some at ph 7. I’m not sure if this would work any better for me vs Adderall XR, or if it would still result in dose dumping. I couldn’t find any info on what ph the Adderall XR extended release portion of the med releases at for comparison. I looked at Adzenys, which is formulated with a different release mechanism (Adzenys is a XR-ODT tablet not beads in a capsule) but is still ph dependent. However, Adzenys is amphetamine base instead of mixed amphetamine salts like Mydayis and Adderall XR. I don’t know if this would make any difference as far as if it would be more likely to release as intended in my stomach or if it would still result in dose dumping.

    I think that pretty much exhausts the options for amphetamine based medications, but there are of course some options in the methylphenidate category with less ph dependent release mechanisms. It’s fairly easy to find information on the absorption of AMP being ph-dependent, but less info is available on the ph-dependent absorption of MPH. When I was first diagnosed, they tried a methylphenidate first and it helped some but not enough, and that’s why they switched me to Adderall. That was 14 years ago though so I don’t know if maybe the dose wasn’t right or if I would respond more optimally to a MPH based medication now. Concerta appears to be not influenced by stomach ph for its extended release delivery system, which is an osmotic pump in a pill instead of ph-released beads like Adderall XR. Daytrana is of course transdermal, but it is only approved for use in children and so I don’t know if my insurance would cover it, and it is really expensive without insurance. Concerta would be covered by my insurance.

    With all of that said, I’m not sure what the best option would be. Looking for insight.

    1. Hi Leo,

      I think you owe it to yourself to try a MPH product. If you try Concerta, be sure to read my blog post on how to get the authorized generic (brand marketed as a generic).

      It might be that, in the end, one of the “legally bioequivalent but we know otherwise” generics would work better for you. But the idea is controlling for all the variables you can first.

      Sometimes, impatience toward seeing improvement and inability/reluctance to teach new skills mean Adderall. It seems to “work” better. But it also has a higher side effect profile, and many people burn out or develop physical symptoms.

      good luck,

    2. Hello Leo after reading your input I would highly suggest that you take your anti-acid medication at bedtime or late in the evening that seems to work very good for me and I take Concerta ER but if I take anti-acid medication during the day I get no effects whatsoever from my Concerta. I hope this helps you e a blessed day ❤️

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