Lactase and Diarrhea: What Users Say

• Thi...
• Taken for 1 to 6 months
• January 5, 2021

Lactase for Lactose Intolerance "This worked once or twice. Four days ago, I became ill after taking these pills, not knowing what my problem was. I was vomiting, had diarrhea, and was shaking. I had other symptoms but I ended up going for a COVID test because I was so ill. Only 4 days passed, and I took the pills again tonight. Here I am, typing this from the bathroom floor, extremely nauseous, and just had diarrhea. DO NOT BUY THESE. It is not worth the bathroom time and how rubbish they make you feel."

• Kel...
• January 28, 2021

For Lactose Intolerance "The first few times I took these, I was fine. Over time, I noticed that I would get bloated, stomach pains, and diarrhea. That’s when I started to get suspicious. The last time I took these pills, I was sure they were the culprit. It started with an unbearable stomach ache and chills. I ran to the toilet, and diarrhea came out of me like water out of a faucet. After I was done, nothing comforted me besides the floor. As I laid on the floor, ugly crying, I could also hear my stomach crying with me. It wasn’t over. I felt the urge to puke coming, so I ran back into the bathroom. I made it just outside the bathroom when projectile vomit sprayed out of me like a dragon breathing fire. I didn’t make it to the sink, but luckily it hit the tile. I puked about six more times, filling up the sink. My husband checked on me, and to both of our horror, he slipped on my puke! There was vomit in between his toes, and I couldn’t even warn him. I was violently ill. I’ll never take these pills again."

• Mic...
• Taken for less than 1 month
• October 13, 2020

For Lactose Intolerance "I wish I would have seen these reviews before taking these pills of misery. The first time I had violent vomiting. My doctor assured me it couldn't be the lactase pills. The next week I tried them again, and I spent another 24 hours with diarrhea and vomiting. Why are these things on the market?"

• Flu...
• October 11, 2020

For Lactose Intolerance "I just wish I'd read these lactase reviews before. I took a couple of tablets, over 2 days at the end of Sept and had 4 days' worth of severe vomiting and diarrhea. I didn't link the 2 at the time and figured I'd had a horrible tummy bug. Fast forward 2 weeks later, and I had a cheese fondue, so I took a tablet to avoid the bloating. Instead, here I am again with horrific vomiting, cramps, sweats, pain, and diarrhea. I was racking my brain, working out what I'd eaten or who has been sick recently in case I had caught something, then suddenly realized the only thing I'd done different was the medicine. Just Googled 'can lactaid cause vomiting,' and I got a sea of pages and people reacting the same way. I will never take or recommend this product to anyone again. I feel terrible, and I'm sad that this isn't more well-known as a side effect."

• Chr...
• March 26, 2020

For Lactose Intolerance "The first few times I tried this product, lactase, I was fine, it helped a lot, so I offered some to my husband. I even bought more. One day, I became so nauseous, began vomiting for the first time as an adult. Threw up about five times, nausea continued, and the next few days diarrhea began. I thought it was a stomach bug. The next week, I took the pill again, and this time I became violently ill, the worst experience of my life! I began vomiting so much it sprayed on the floor and walls, then I began sweating and had trouble breathing, I had stomach pains and liquid diarrhea. I started getting chills. This was my night. I do not recommend these pills to anyone alive. HC and the FDA should be informed, and the manufacturers should not be allowed to make this product ever again. Judging from the other comments, I'm not the only one."

• Ugh...
• April 19, 2021

For Lactose Intolerance "I’m new to the lactose intolerant world. I made it to 50 without any dietary issues. I started having tummy troubles after eating yogurt or cheese, so I tried Lactaid. My first experience was a week ago. I had an iced coffee with cream and popped a pill for the first time so I could enjoy the coffee without the belly cramps. A couple of hours later, I felt off. Something wasn’t right, and then the vomiting started. I just assumed it was something I had for breakfast and left it at that. Fast forward 1 week. I’m out for pizza for lunch and give the Lactaid another try. Biggest mistake of my life! I barely made it home before the violent vomiting started. I had the sweats, the shakes, and I couldn’t even pick up my head or open my eyes without getting nauseous. It took over an hour to stop the multiple vomiting and diarrhea sessions. I looked up the side effects, and my symptoms weren’t mentioned anywhere. Thank you all for sharing. It’s nice to know it wasn’t just me!"

• Som...
• Taken for less than 1 month
• September 27, 2019

Lactase for Lactose Intolerance "I have tried these pills twice. Once last week, and I got violently ill, vomiting for 5 hours straight, and then diarrhea about 4 hours later. The vomiting was so bad that I couldn’t hardly breathe in between. I got cold chills and was sweating profusely. It was absolutely awful. I tried again last night, not knowing what exactly caused the illness the first time. Same exact thing. No way will I ever take another one of these or suggest them to anyone."

• Mad...
• Taken for less than 1 month
• September 18, 2020

For Lactose Intolerance "This product should be reported. After seeing all of these reviews, I'm very angry. I got awful diarrhea and vomited profusely after taking this product, multiple times. This has happened to many others. This product needs to be taken off the market and out of stores now! The feeling you get when you take this product is absolutely awful. -999/10."

• Aan...
• April 20, 2020

For Lactose Intolerance "I have very mild lactose intolerance, and for the most part it doesn’t affect my daily life other than getting a stomach ache after a particularly dairy-heavy meal. However, my girlfriend has it pretty bad, so we usually have this stuff on deck. A few days ago, we had a cheesy dish, and I thought to take one of these because it couldn’t hurt. An hour later, I was incredibly nauseous, had diarrhea, and even had a low-grade fever. I was so miserable I cried, but thought it was the stomach flu. I was fine for a few days, and then tonight I took a lactaid, and we are in this same position - nausea, diarrhea, cold sweats, etc. Something told me that maybe it was the lactaid, but after doing research, this was the ONLY website where people shared my experience. I will never be taking these again. Also, I know it’s not the lactose itself because this has NEVER happened before. Wish me luck as I take a Pepto-Bismol and try to ride this terrible night out."

• Sco...
• February 6, 2017

Lactase for Lactose Intolerance "After not having many issues with any dairy other than ice cream, I decided to try Lactaid in order to be able to enjoy the delicious treat of vanilla ice cream once more...but I regret everything now. Not only did it not do Jack squat, but my symptoms of lactose intolerance are even worse now. Usually, I can get away with just a little bit of gas, and I'm fine, but now I have nausea, diarrhea, gas, and bloating. Worst decision ever!!! This product deserves negative stars!!!"

• Che...
• January 13, 2021

For Lactose Intolerance "I started taking lactase pills to help with the effects of lactose intolerance. The first three or four times I took them, they didn't seem to do much in the way of easing the symptoms of lactose intolerance, and my stomach felt a little nauseous. The next time I took it, I became so ill I thought I had the flu. When I took it again, I became sick again with an upset stomach, diarrhea, headache, and muscle aches. So much worse than the symptoms I get from eating lactose. I will never take this again!"

• Stu...
• Taken for less than 1 month
• June 23, 2014

Lactase for Lactose Intolerance "My 10-year-old son would get stomach cramps and diarrhea every time he tried milk. We tried Lactaid on two different occasions a few weeks apart, and both times it caused vomiting. Obviously, something in the pills does not agree with him."

• Mom...
• Taken for less than 1 month
• January 31, 2020

Lactase for Lactose Intolerance "My story sounds like all the others. I tried this product 2 separate times. The first time I was at work. Took the Lactaid with my lunch and one hour I was sick. Vomiting and diarrhea. I had to leave and go home. I did not think it was the pills. I tried it again a few months later and same thing. Vomiting and diarrhea. I had bought a box of 60 chewables that will go to trash. I would not recommend this product to anyone."

• Tin...
• Taken for less than 1 month
• April 30, 2019

For Lactose Intolerance "I first tried this 6 years ago. Two hours after taking Lactaid, I was vomiting with diarrhea at my daughter's house. I didn't even connect the two. Just assumed it was something I ate, not necessarily from dairy. Two weeks later, I tried taking it before my lunch at work. Within the hour, I was vomiting. I wondered if it was the Lactaid, but thought that was impossible. Fast forward 4 years, and I decided to try again because my lactose intolerance was getting worse. Nope. Same symptoms. So a few days ago, I ordered a different brand of digestive enzymes. Lactase is in this one. I tried this afternoon. I am now severely nauseous with stomach pain. I happened to have some Zofran on hand, so I took it and hopefully I won't vomit! Never again! The 'cure' is worse than the disease!"

• Aha...
• Taken for 1 to 6 months
• November 11, 2018

Lactase for Lactose Intolerance "I developed a lactose intolerance around the time I turned 25. I cut out all dairy products until a few months ago, I’m now 32, until a friend gave me Lactaid. If I’m eating a cheeseburger and I take one fast-acting capsule, I’m fine. If I’m eating ice cream, potato soup, chicken Alfredo... I have taken two. I have taken two now three separate times, and both times ended up with severe, painful vomiting/diarrhea. Much worse than if I had just eaten the food without the Lactaid. I think it’s a great product if it works for you, but I would rather not eat dairy than projectile vomit."

• Mz ...
• Taken for less than 1 month
• December 27, 2017

Lactase for Lactose Intolerance "This is my second time trying this pill. The first was about ten years ago. Therefore, I brushed the side effects to the side and thought it was just me. This time, I took two pills, and all I can say is that I will never try them again! Maybe it’s just me, but I vomited, had diarrhea, and my stomach hurt for hours. I prayed to the porcelain queen like no other. All I wanted was a mini bar of ice cream, but after feeling so bad, I’d rather deal with the side effects from having the ice cream."

• Anonymous
• September 22, 2018

For Lactose Intolerance "I thought I was crazy, but after reading the comments, I see that I am not alone. They say that there is no side effect for this product. I tried different brands, and they all made me very sick. I was vomiting and having diarrhea for the whole night (3 different times before I realized it was the pills). It felt exactly like gastroenteritis."

• N61...
• Taken for less than 1 month
• June 12, 2023

Lactase for Lactose Intolerance "This made me so much sicker than the discomfort I experience from eating dairy. Twice now I've ended up with overwhelming nausea, vomiting, and diarrhea. I only figured it out because both of these happened after using Lactaid. There's no warning on the box at all, but trust me, it's horrible. It takes about 3 days to feel better."

• Phi...
• June 9, 2020

For Lactose Intolerance "I so, so wish I had read these experiences. Have taken this maybe 3 times in an attempt to get less gas and bloating with a bowl of ice cream. The 3rd time, a few hours after the dose, I was asleep and woke up to gnarly stomach cramps. Soaked in sweat, pale green, gagging with nausea during diarrhea. Really horrible. Very dizzy, thought I would pass out. Never again. These pills always gave me weird stomach feelings, but I attributed it to the little bit of dairy. Nope, I’d much rather have some gas pains, lol."

• Acc...
• Taken for less than 1 month
• May 11, 2020

Lactase for Lactose Intolerance "I have taken this pill 3 separate times. Every time I have taken this, I have severe cramps and diarrhea. Horrible diarrhea! The first two times I took this, I thought it was something I ate that was bad. Now, the third time dealing with this, I know that it’s the pills. When my stomach wakes me up in the middle of the night so I can spend an hour in the bathroom, it is not fun. It usually lasts for 24 hours, but it’s embarrassing to tell my boss I can’t come in because I’m on the toilet. Never again will I take these, and I would never recommend them."

• Chl...
• November 3, 2020

For Lactose Intolerance "I’ve used Lactaid before and can’t remember having symptoms from it. I recently went on vacation and decided to buy some in case I ended up having any dairy. Looking back at just a couple of days ago, I understand why my stomach hurt and why I was nauseous. Today I had just a little bit of cheese and decided to take a Lactaid. I all of a sudden felt nauseous and had stomach cramps. I went on a walk and my cramps wouldn’t go away. I was getting chills and almost some cold sweats. Then, the diarrhea... It didn’t add up that my stomach would hurt that bad from half a slice of cheese. It sounds like so many people have experienced similar symptoms. I won’t be taking this again... I have tried the Equate brand and I don’t remember ever having issues, so I’m curious if there’s a difference in ingredients causing this problem. I’m too scared to try again now!"

• Hug...
• Taken for less than 1 month
• March 14, 2019

Lactase for Lactose Intolerance "I took the chewable Lactaid on three occasions. The first time, I had to miss work for the remainder of the day as I was vomiting nonstop. Next time, the same. The third and last time, I ended up in the ER, I was in pain, had a fever, diarrhea, and vomiting at the same time. My wife was the one who recalled that all three times I was sick, it was when I used Lactaid Fast Act chewable tablets. NEVER AGAIN. I did not believe it, so I tried eating the cheese I had that night without Lactaid, and I did not have any symptoms except the usual bloating I get from lactose. I prefer bloating to spending a night hooked to the intravenous fluids."

• So ...
• Taken for less than 1 month
• November 12, 2021

Lactase for Lactose Intolerance "This is the second time I used Lactaid. OMG, did I get sick! Within one hour of taking it, I was having diarrhea. Then came severe vomiting! Had no time to lift up my toilet seat! What a freakin' mess! I was so thirsty, but each time I drank water, back to hugging the toilet I went! Had chills and a low-grade fever. I have no idea why this reacted the way it did, but I will never take it again! PS. I finally discovered why I had gotten sick over my sister's house a month ago. Thought I had a 24-hour bug. But finding out today, it was the Lactaid she gave me!"

• Amy...
• May 12, 2019

For Lactose Intolerance "I would not recommend lactase to anybody! I had taken these pills a couple of times and felt fine, but the third time I have taken these, I am violently ill. I have never thrown up like this and had such bad abdominal cramping and diarrhea. I thought it was caused by the dairy I ate, although I had never thrown up from my intolerance before. But after reading several other reviews on here, I know it is the pills that caused this. I have no idea what is in these causing so many people to feel this way, but I would way rather take my symptoms of bloating and indigestion compared to the pain these pills brought me."

• VMo...
• Taken for less than 1 month
• December 15, 2019

For Lactose Intolerance "I tried this pill (Walmart Equate brand) on the advice of a friend who heard about it but hadn’t used them herself. I tried them for the first time last Thursday right before I went to a hockey game. Within 2 hours, I was extremely violently ill! I’ve never vomited like this in my life. I threw up for hours, and then came the diarrhea. It was so painful and maybe one of the worst experiences of my life. I couldn’t eat for about 24 hours. Today, 3 days later, I took two pills before having milk. Here I am now, 2 hours later, vomiting again! I do not recommend this product."