Lactose in Medications: What You Need to Know


This article on lactose in medications was written for us by the lactose intolerance expert, Steve Carper of Planet Lactose.

Lactose is a sugar, a slightly-sweet sugar. It is only about one-seventh as sweet as sucrose, ordinary table sugar. Oddly enough, this is a good thing to many in industry. Lactose allows a bit of pleasant sweetness to be added to products, without overwhelming them with an overly-sweet taste. Commercial bakers can sprinkle lactose on the tops of bread and let it caramelize to a beautiful golden-brown. Food processors can add lactose (or whey, which is mostly lactose) to add taste and texture to foods without affecting the primary taste of the food.

Best of all, lactose is made from whey, and whey is a waste product in the cheese-making process, so it’s really cheap.

That’s why lactose is used so often in pill-making. The extremely tiny amount of actual working ingredient in a medication needs to be surrounded with fillers that bulk it out to be large enough to handle. A substance that is mostly tasteless but with just enough sweetness to balance out the bitter taste of many medications is great. That lactose can be formulated to break down in the stomach to release the medication makes it nearly ideal.

Lactose Set to Star in Even More Medications

Literally hundreds of branded prescription medications use lactose as a part of their formulations. If you add in generics and over-the-counter drugs, you probably have thousands of medications that include lactose.

And there will soon be more rather than fewer pills that use lactose.

Phil Taylor on wrote Roquette wins US patent for Starlac in novel dosage form about a new and improved way to dispense medications.

French company Roquette has been awarded a US patent for a dissolve-in-the-mouth drug delivery technology that makes use of its novel Starlac excipient.

Use of the excipient could allow the creation of tablets that are hard and resistant to damage during handling, yet still disintegrate quickly in saliva after dosing.

The US patent, awarded to Roquette earlier this month, covers a solid dose form based on lactose and starch, the constituents of Starlac excipient, alongside one or more active pharmaceutical ingredients (APIs).

Xavier Duriez, senior project manager at Roquette, told that almost all ODT products on the market use mannitol as a diluent, but that in some cases Starlac could be used as a good alternative.

“Starlac is preferred for ODT and chewable formulas where palatability is a ‘must’,” he said, adding that the excipient provides a creamy mouthfeel that mannitol doesn’t provide.

Starlac, a mixture of 85 per cent lactose and 15 per cent natural corn starch, was first introduced in 2002.”

Of course, the mere granting of a patent doesn’t mean that any products using Starlac will hit the market any time soon. But unless there is a serious bug with the project, it’s too good an idea not to come to pass.

How Much Lactose Is in Medications?

What does this mean for those who are lactose intolerant? Not as much as you might think. Only a tiny amount of lactose is present in any one pill. One study I read estimated that the average pill had 25 mg of lactose. You’d need to take 12,000 such pills to equal the lactose in an eight-ounce glass of milk at that rate. [Editor Note: By our calculations, this is actually 500 pills.]

A very few people might still be bothered by this tiny amount, especially if they have to take many such pills each day, as the elderly or those with serious illnesses must do. All I can suggest is to take a lactase pill along with the medication to see if that helps.

Is it a Concern for Milk Allergies?

Those with a dairy allergy also need to be somewhat concerned, but with the same caution. Medical-grade lactose is extremely pure and not likely to be contaminated with the dairy protein that causes problems. Extremely anaphylactic people should certainly talk with their doctor before taking any pills with lactose. Those with lesser allergies and symptoms probably can take pills that contain lactose with no problems. But certainly check to see what alternatives there are.

About Author

Alisa is the founder of, Food Editor for Allergic Living magazine, and author of the best-selling dairy-free book, Go Dairy Free: The Guide and Cookbook for Milk Allergies, Lactose Intolerance, and Casein-Free Living, and the new cookbook, Eat Dairy Free: Your Essential Cookbook for Everyday Meals, Snacks, and Sweets. Alisa is also a professional recipe creator and product ambassador for the natural food industry.


  1. Is there a link to the study identifying 25mg on average of lactose in a pill which equals that 12,000 pills need to be consumed to equal the amount in a 8oz glass of milk? I have seen other articles reference only 1000 pills would be equal. Thank you

    • Hi Jacky, I need to update this post to ensure all data is still accurate. It was written by Steve Carper (an expert on LI), and he used the following sources (not sure which one applies to this specifically):
      American Academy of Pediatrics Committee on Drugs. “Inactive” ingredients in Pharmaceutical Products: Update (Subject Review). Pediatrics. 1997;99:268-278
      Brandstetter RD, Conetta R, Glazer B. Lactose intolerance associated with Intal capsules. N Engl J Med. 1986;315:1613-1614
      Higham MA, et al. Determination of the minimum dose of lactose drug carrier than can be sensed during inhalation. Br J Clin Pharmacol. 40;3:281-82 [I had an earlier citation of LI from a nasal spray, but I can’t find it now. If anyone out there knows of it, please send me the complete reference. Thanks.]
      Lieb J, Kazienko DJ. Lactose filler as a cause of “drug-induced” diarrhea. N Engl J Med. 1978;299:314
      Malen DG. Parnate formulation change. J Clin Psychiatry. 1992;53:328-329
      Petrini L, et al. Lactose intolerance following antithyroid drug medications. J. Endocrinol. Invest. 1997;20:569-570
      Van Assendelft AH. Bronchospasm induced by vanillin and lactose. Eur J Respir Dis. 1984;65:468-472
      Zeiss CR, Lockey RF. Refractory period to aspirin in a patient with aspirin-induced asthma. J Allergy Clin Immunol. 1979;72:633-636

      I just looked up the lactose in milk, and calculated and it looks more like 500 pills to me based on 25mg.

    • For medications, all ingredients must be available to the pharmacist and to you on request. Top allergens (like milk) are typically noted in their system. But medications do not fall under the same allergen labeling laws as food.

  2. Lesley Margiotta on

    I am vegan and have discovered lactose monohydrate in the medication I was just about to start taking in an HRT tablet. Would the doctor be able to prescribe something similar without the lactose mnohydrate or does all prescription drugs contain some form of lactose in them ?

    • I couldn’t tell you on a specific medication but different brands of the same medication and generics often have different filler ingredients. You can call a pharmacy and ask as they should have all of the ingredients in a database.

  3. I have an allergy to milk. And taken any medication with milk makes me unwell, stiff sore joints and watery bowel movements. Even the smallest amount.

    • Yes, brand name Allegra does not contain milk. Other allergy medications which do contain milk in the form of lactose monohydrate include but are not limited to Zyrtec, brand name and generic, Claritin, and Xzyal. I have a milk allergy and I have personally found that I cannot tolerate any medications with lactose because I develop breathing problems, although I am not anaphylactic.

        • Roberta Gottfried on

          Thank you for this information. I am highly allergic to lactose, dairy, whey, etc. This explanation explains why I felt worse taking Claritin — the lactose. I switched to Allegra and do not have any side effects.

  4. I was about to begin a weekly regimen of Fosamax for osteoporosis until I read the ingredients. One of those is anhydrous lactose. I looked for a specific definition and it also led to these comments and responses. I am both lactose intolerant and have a milk protein allergy, so taking Fosamax would probably be a nightmare for me. Thank for all your help, Alisa, with GoDairyFree. It has saved me from much misery and complications.
    If you know anything more specific about Fosamax or other related meds I could use and tolerate, please let me know.

    • I’m so glad to hear that my work is helpful for you AND that you discovered this issue with Fosamax before taking it! I don’t have any other details on it, but would speak to the pharmacist or your physician about options. They each have access to the ingredients and should be able to look up other options, including generics, that may work instead of that particular name brand medicine.

  5. Paul Tofanelli on

    Intact Lactose entering the Blood Supply
    is Highly Addictive to the Central Nervous System
    and Human Body
    By Paul C. Tofanelli
    April 28th, 2016

    Galactosemia has only been known as a Hereditary Disease. Galactosemia is a disease in which a persons body cannot process Lactose correctly. I have discovered an Adult strain that is highly addictive to the central nervous system and our bodies. This strain is caused by Intact Lactose entering the blood supply.

    There has been a study on absorption of intact lactose into the blood stream of infants with damage to the small intestinal epithelial barrier that caused disease in several organs including the kidney.

    I have found a new mechanisms for lactose entry into the blood stream in Adults that causes addiction and disease.

    Intact Lactose is entering the blood stream by Medications in the Small Intestine byway of Stearic Acid and or Magnesium Sterate, melting point is 156F. Stomach acids do not break down Stearic Acid and or Magnesium Sterate. Lactose is protected from lactase and enters epithelial barrier into blood supply by a form of Leaky Gut Syndrome.
    Intact Lactose is entering the blood stream byway of injection. 65% to 90% of a Heroin injection is Lactose.
    Intact Lactose is entering the blood stream byway of the Nasal Cavity.
    Intact Lactose is entering the Blood stream byway Inhaling “Drug use smoking”.

    Intact Lactose in the Blood Supply is causing Addiction to the Brain and Disease in the Body. Withdrawal symptoms can be extremely severe depending on the amounts of Intact Lactose that has entered the blood supply and how long it was occurring. Withdrawal durations can be weeks, months, or years.

    Thank you,
    Paul C. Tofanelli

  6. I guess I am one of those ”rare cases’ who are allergic to the small amount of lactose in over-the-counter and prescription medications. I recently found out that I have a milk allergy. I had no idea that the ‘small’ amount of lactose in over-the-counter and prescription medication would be of any concern. I used a generic antacid that had The same active ingredients as Pepcid. I had an allergic reaction, and after realizing that the last thing I had ingested had been the generic Pepcid I went back and read all of the Ingredients including the inactive
    ones. There were two types of lactose. Anhydrous lactose and lactose monohydrat. I have also realized that I am having a reaction to other medications including those that I take at bedtime …Ironically I was diagnosed with sleep apnea because I was having trouble breathing at night. Since then I have had an allergy test performed by my ENT after being unable to find a cause for persistent ear pain a sinus problems. I found out about the milk allergy . I am trying to find more information about the ingredients and inactive ingredients in prescription medications, but I am having difficulty. Do you have any suggestions?

    • Hi Debbie, a medication / supplement list is something I looked into creating a few years ago. Unfortunately, drug companies are even worse about changing ingredients and disclosing allergens and processes than food companies. My first efforts were like trying to hit a moving target. It is very odd that you would react to milk sugar (lactose) with a milk protein allergy, but stranger things have happened! In general, the milk ingredient list I have here on the website and in my book should work for medications, too. It lists all of the forms of milk used in food –

      • Hi Alisa — If you’ve had a tick bite, the combo of milk sugar AND milk protein allergies is not so surprising. After having Lyme disease, I’m allergic to milk and red meat, i.e., everything mammal-related. Tell me that wasn’t a hard one to figure out! Also, I have same issue with adverse reaction to OTC and prescription drugs containing lactose.

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