Whey Protein Side Effects

Consuming enough protein is one of the requirements to build muscle, but consuming too much can develop some of the known whey protein side effects.

A normal person requires something like 0.5 grams of protein per pound of his or her body weight.

Bloating - Whey protein side effects

Bloating is the most common of the whey protein side effects

A person that is trying to build muscle requires more, around 1 g per pound.

Professional bodybuilders can take even 2 g per pound.

Taking whey protein supplements can help you consume the amount of protein that you need to achieve your goal of building muscle mass, but don't be a fool thinking that the more protein you take in the more muscle you build.

As for everything, too much is never healthy. You always have to keep an eye on moderation if you want to avoid bad surprises after a prolonged use.

Even if something is very important for your body, too much of it will most likely be harmful as well.

I am thinking of water...

How many times did we hear "Drink plenty of water"?

Water is essential, but I've also heard of people that died from drinking too much water during a contest!

Whey Protein Side Effects

Although whey protein is a pretty safe supplement, like any abuse too much of it is going to develop some unpleasant side effects.

Lactose Intolerance

Lactose intolerance is one of the most common whey protein side effects.

I know many people that experience this problem when they take whey protein shakes.

If you are one of those, your best bet is to go with whey protein isolate because it contains only 1% of lactose, which is very low compared to the typical 5-6% or regular whey protein.

Usually people with lactose intolerance switch to casein protein, and that seems to go much easier on their stomach. I tried it and I tend to agree.

Dymatize Nutrition Elite Shake, Casein Chocolate Peanut Butter, 4 Pound

Intestinal Irritation

This is probably related to the lactose intolerance, even though some that are not intolerant still experience side effects like diarrhea and flatulence.

Yeah, come on admit it, you had that too!

It's very common to develop increased intestinal gas during a whey protein cycle.

Don't be surprised if you hit the bathroom much more frequently than you used to and if your feces suddenly become softer than usual.

Hint: I experienced big improvements when I started taking whey protein shakes with water rather than milk, especially near bedtime.

Click here to read more about whey protein with milk vs. water from my blog.

Kidney Stones and Kidney Failure

Kidney stones is one of the worst consequences of a high protein-low carbs diet, which doesn't sound so bad at first, but after you interview people that went through it you definitely change your mind.

Literally, if you get kidney stones you have to go "through it". Kidney stones are deposits of calcium in your kidneys, and somehow your body has to get rid of them.


You basically have to pee them out, which is so painful according to those that experienced it.

Have I? No.

And I am trying to prevent it by taking moderate quantities of whey protein and drinking plenty of water.

Especially when on a high protein and low carbs diet (meaning basically no carbs) people are proven to excrete a large amount of calcium in their urine.

Calcium is provided by the bones, and if this continues for a long time it can cause osteoporosis too.

Not such a good idea huh?


While a high protein and low carbohydrates diet have been proven to help lose fat in the short term, a prolonged use of this type of diet can lead to enter a ketosis state.

What is ketosis?

It's a metabolic state where your body burns more fat as a source of energy due to the lack of carbs. This is dangerous because it stresses the liver and causes the destruction of muscle tissues.

Not only, prolonged ketosis state can cause kidney stones as well, and kidney failure.

If you are consuming lots of protein you can avoid ketosis by eating at least 100 g of carbs a day. That way you give your body something to burn for energy.


This is one of the whey protein side effects that I have personally experienced.

Not only with proteins, weight gainers as well.

Bloating, enlarged stomach, a belly that sticks out even if you're not fat.

Call it what you want, but that's the side effect, my belly looked like a small balloon.

I remember thinking "I am not fat, so why is my belly so big?". I asked around, I documented and I found out that supplements can do that.

The good news is...it only takes a short time off whey protein shakes or weight gainer shakes to go back to normal.

If you want though, you can always try some anti-gas and anti-bloating supplements like this:

Gaia Herbs Gas & Bloating, 50 Dietary Supplement Capsules

Reviews are really promising. That way you could eventually keep taking protein without whey protein side effects!

Best Brand to Avoid Whey Protein Side Effects?

Now you're probably wondering if all brands are the same, or if there is at least one that is a bit better and could reduce all the side effects that you are experiencing.

I can tell you what works well for me, you can try it, but everybody is different.

The best I found is the BSN Syntha-6.

I know that I have very little bloating, basically no other side effects, and I digest it easily.

Reviews are also very good for most people, but you may have to try different brands before you find the right one for you.

Buy small containers, so you can change frequently. And if you find a flavor that you like, don't stick to it for too long, or you will get sick of it sooner or later.

I keep 2-3 different flavors and rotate frequently!


So, yes you need lots of protein in your diet if you want to grow muscle, but be careful and make sure you don't abuse it.

Whey protein side effects can be uncomfortable (lactose intolerance, intestinal irritation, bloating etc.) and also very dangerous (kidney stones, kidney failure, stress on the liver and ketosis).

Be always moderate in whatever you do, it's the key to stay healthy and avoid serious consequences.

Some are scared to take whey protein supplements because they've heard stories about whey protein baldness side effects...well, I did some research I I came to the conclusion that it's a myth.

Click here to read about whey protein baldness side effects.

Do you agree with what you just read?

Have you ever experienced any of these side effects or others that I haven't mentioned?

Drop a line and let me know!


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68 Responses

  1. Also, I started to drink vegetable (in the same time I started my amino acid supplements) juice in the morning on an empty stomach. I also read some article that this can also cause gas and bloating? Contents of the juice are Carrots, cucumber, celery, bitter gourd and apples. Any feedbacks highly appreciated. Thanks.
  2. Avatar gigi
    Aww..now i know why i feel so bloated and heavy every after taking whey protien.feel crap everytime.grrrrr
  3. Can we take supplements on the days when we dont workout as well ?
    • Cristian Cristian
  4. I also have a hard time with protein. This has been a helpful post.
  5. Avatar nihal
    when i take whey protein isolate after some time my skin is start itching
  6. can u suggest me which is the best supplement to increase my arms and body with out any side effects
    • Cristian Cristian
      I would go with a weight gainer to begin. But you have to work out muscles for them to grow, nothing else can target muscles. Only targeted exercises.
  7. I am lactose intolerant and I therefore started with casein. I had such a bad time... I was constipated all the time. I then switched to whey protein, but the whey p from Optimus Nutrition that does not cause any problems with my intolerance. I feel very well with it.
  8. Avatar Raja
    I hit by Bloating as side effect of whey protein. My tummy got bigger as compare to my rest of the body though my diet is so normal :( any suggestion.....
  9. Avatar money
    Yes.I am facing kidney stone problems from last 5 years which has worsen my life. Till now more than 25 stones have been excreted by my urine and it pains very badly. Now, whenever I take whey protein I have pains in my kidneys and I am operated 2 times also. So,without knowing your body,never take any kind of body supplements.
    • Cristian Cristian
      Thanks for sharing this!
    • where exactly you have pain....???? i have at lower side of my stomach.....is mine also same....]???
  10. Avatar Jimmy
    I take Clear Protein 1 scoup a day after my workout and i go diarrhea what does that mean??
    • Cristian Cristian
      Maybe that's how your body unfortunately reacts to whey protein...
  11. Avatar fayyaz
    How many scoops of Whey protien is suggested, if you workout like 1 hour per day and 6 days a week. like i take natural form of protien as well, like egg whites and chicken..
  12. Avatar Obnoxious Cadaver
    Increasing your fibre intake is the best way of offsetting the flatulence associated with high protein intake. Taking metamucil immediately before your protein shake works wonders, as does increased amounts of fruit and veg
  13. Avatar parvaiz
    Hello sir i have a lot of pain in stomach should i eat mass gainer if i eat mass gainer then which one is the bst mass gainer
    • Cristian Cristian
      My favorite and with the least side effects is Syntha 6! A mix between whey protein and weight gainer. <a href="http://www.amazon.com/BSN-SYNTHA-6-Protein-Powder-Strawberry/dp/B002DYJ1D8?tag=bm1010d-20" target="_blank" rel="nofollow">Syntha 6</a>
  14. Avatar parvaiz
    I have eat mass gainer 5 mnth ago but from 2 mnth i will not going to gym and i lost wait and previous 2 weeks i have lot of pain in my stomach so i was thinking to restarting gym so will u plz sugest me wat should i eat mass gainer or protein
  15. Avatar abhishek
    hey admin i took about 2 kgs of weight gainer when i was around 16 now m 18 and i was 50kgs before i joned gym 1 month after gym i took ON gold standard whey 2lbs and gained 5kgs more that is 55kgs but my arms r like still skinny but my belly and abs area is blotting what u say shd i continue consuming whey (as u must know ON's gold standard whey is the best u can found in market).
    • Cristian Cristian
      If you take it with milk, switch to water. Maybe reduce the dosage and try to add some cardio, and if arms are skinny you just need to do more arms workout. Then it depends, some people have a harder time than others to build arms muscle, or chest muscle etc.
  16. Avatar abhishek
    Thanks for your response mate N yeah i used to take 1 serv i.e 30grms of whey with milk after workout And my trainer dont let me do cardio coz of skinny body As you said start taking whey with water ./. Means you suggesting me to continue with whey right.!
    • Cristian Cristian
      Yes whey is the leanest. Try to drink lots of water too. Unfortunately bloating is a known whey protein side effect. At least you shouldn't gain fat. Do cardio in the morning even before breakfast so you burn the excess fat. If you do it later in the day you burn carbs instead of using them for energy. And don't tell him lol
  17. Avatar abhishek
    Ya i will, Like your post?
  18. Your lower left abdominal pain could be a kidney stone. Kidney stones can produce pain in the back and abdomen, and it can feel like it is worse on one side or the other. The pain can be so intense as to cause sudden nausea and vomiting. The pain can have a sudden onset as the "stone" moves into a ureter of the body. The stones are composed of little crystals which "catch and claw" their way down through these "tubes" through which urine leaves the body. There may be blood in urine as a symptom of these stones passing as well. The pain intensity will depend upon the size of the stone. If you suspect you have a stone, it is a medical emergency that needs to be seen by a professional. Along with a urinalysis and other lab tests, a sonogram will be done to determine many things, but to of most importance, if the stone is too large to ever pass completely. So a doctor's visit should be scheduled if you think you have a kidney stone. There are different medications that can be taken to help, such as one which dilates the ureters making them larger so that a stone or stones can pass more quickly.
  19. Avatar abhishek
    if the stone is not so big that it needs medication it can be cure by drinking moderate amount of beer / Ever notice how you always end up running to the bathroom every time you have a few beers? Alcohol stimulates the kidneys to work harder to excrete the by-products of alcohol metabolism and this allows you to urinate more frequently. In fact, urinating is actually a natural way for the kidneys and bladder to cleanse themselves; thus, urinating because of drinking a couple of beers stirs up the bladder, prevents the coalescence of mineral crystals, and actually excrete those minerals while they are still at their smallest/. Source- http://www.benefitsofbeer.com/beer-and-kidney-stones.shtml
  20. Avatar Craig Rivers
    I am 64 years old and am doing the Long Trail in Vermont fall of '16. I have increased my diet with protein and also take whey protein shakes everyday for the past two months. I feel like a million bucks have increased my bench press by over 30%. I have actually seen some muscle mass. I am now experiencing bloating and nausea in the evening. Should I cut the milk out? Also should I only drink the whey shakes on my workout days (5days a week) and not drink it on weekends? Or should I go off it totally until symptoms resolve? My son who is a power lifter also recommended amino acids. Should I wait until my gut straightens out before I start amino acids. Do you have any recommendations on what brand to use?
    • Cristian Cristian
      Craig, I would definitely switch from milk to plain water. I found that milk and protein are a bad combination, the increase in side effects is noticeable. Try water with your powder, and take it only on workout days. I also suggest to switch flavor often, I get sick of the same taste quick! Have 2 or 3 different flavors at home, and change often, that will help with nausea. Water will help with bloating. My favorite with less side effects is Syntha-6. Copy and paste this link: http://amzn.to/1WMVPmN
  21. Avatar jackson
    Hi Critsian, I am 5.11 and weigh around 210lbs and with waste around 40inch. Working hard at gym and taking optimum nutrition gold standard whey protein as well. I don't need mass, just I have to reduce weight. Should I quite taking supplement protein or should I continue. Appreciate your reply.
    • Cristian Cristian
      Hey Jackson, good question, I beat there are many interested in this as well. If you take in enough protein with your diet, there's no need to spend money and experience whey protein side effects. As you said, mass is not your goal. On the other hand, you still want to build muscle because more muscle helps burning more fat. Imagine your body like a car: a big engine requires more gas to run, and big muscle require more energy too (that come from fat burn).
  22. Avatar Carlos
    Bloating is also created by milk, just cut the milk and you will have less bloating. (I have a lot of bloating during seasons I use milk, just cut it off and you will be better)
  23. Avatar Carlos
    Bloating is created also from milk, 50% comes from it. Used to drink around 1.5 l per day, started to have some really bloating issuse, now just cut it off and I'm much better.
  24. Avatar Nawid Yousuf
    I have been working out from 6 months and i want to take a protein without Whey protein which one you suggest for me and which one i should take for competitions and it's about 2 and half months.
    • Avatar Craig Rivers
      I take Veggie Lite and feel great. With whey I had bloating, bowel habit changes. It was terrible it took 3-5 days off it to feel better.
  25. Avatar Nawid Yousuf
    Hello Cristian, I would like to know about Iron Mass by Arnold Schwarzenegger and i want to take that protein what is you suggestion for me i have been working out from last 6 months.
  26. Avatar Calvigo
    On exercise days, do I drink my whey protein shake with my breakfast or just the shake and skip breakfast?? What do you recommend?
    • Cristian Cristian
      Honestly I would drink it right after workouts!
  27. Avatar P Gupta
    I got diarrhea and headache after my first glass drinking protein shake.. Along with boating what to do? Should I drink with water rather than milk? should I stop drinking it? Have a huge bottle :(
    • Cristian Cristian
      Water will definitely reduce the side effects
    • Which brand and from where you buy that Are you sure it is genuine?
  28. Hi Cristian. Thank you for your great article. Syntha-6 is great. But it's protein blend (which also included soy protein, casein & egg protein as well) ,not 100% whey protein. And if you're lactose intolerance, i suggest that Syntha-6 Isolate is better than Syntha-6 (it's more expensive, of course).
    • Cristian Cristian
      I agree. Regular Syntha-6 leans a little bit towards a weight gainer too.
  29. Avatar Anto SolomenBen
    Hello,Cristian... I am also workout in GYM...I am almost 80kg and 23 years old...I need to make my arms big I am satisfied with my chest but arms no way...let me try whey protein...what you think about it...?
    • Cristian Cristian
      Protein is good to build muscle, I would focus more on arm exercises in this case though.
  30. Avatar Analog
    I have also found that the artificial sweeteners in these products make Me Bloated. When I tried One of them that had no artificial sweetners in it, I felt great. No bloating, stomach and throat irritation etc
  31. Avatar Vishal Chawla
    I have few extra inches on my stomach and sides where are my hands and legs are lean . As i am hitting gym now to reduce the same. Can you please suggest me with some supplements to make my body fit and shall i take whey isolate to increase my over all muscle size. Please guide me Cristian.
    • Cristian Cristian
      Lean protein is always good to build lean muscle. Lean muscle is also a natural fat burner itself, so yes (but don't exceed). To get rid of those inches you should definitely include some cardio too! Hope this helps!
  32. Avatar Gaurav
    hello Cristian..I just started taking whey protein and today is my second day of having ON whey protein gold standard chocolate malt flavor(with water).Feeling stomach ache,cramps,headache.I am 5'8'',82 kg weight.Can you suggest what remedial steps shall i take in order to avoid those symptoms.I am not lactose intolerant.
    • Cristian Cristian
      Hmmm you already take it with water which should reduce the side effects. Other than that I could think of 2 things: 1. You may need some time to adjust, symptoms may disappear after your body gets used to it 2. Try changing brand (I found the Syntha-6 to be the best)
    • Avatar abhishek
      From where you buy that? How much lbs and at what rate?
      • Cristian Cristian
        I buy my supplements from amazon. Copy and paste this link http://build-muscle-101.com//bsn-syntha-6-reviews/ or type syntha 6 reviews in the search box (top right of the screen).
  33. Avatar Craig
    You need to use whey isolate. Straight whey will mess up your GI tract upset, bloating, and either constipation or loose bowels. Only use the protein supplements immediately after workouts. It helps full you up and build mass hope this helps
  34. Avatar mahtab
    hello. my husband after 20 dsys using protein whey have had erectile problem for the first time. can whey protein affect on erection in men?
    • Cristian Cristian
      I have never heard of it, and I don't think so. I'd say it's unrelated. There is always a first time and it's totally normal at any age. It could depend on a hundred of different reasons and circumstances.
  35. Avatar Jon
    Hey cristian, is there any specific way to find out if your stomach is bloated due to body fat or gas?
    • Cristian Cristian
      Well I think it's pretty easy to determine. You can feel if you have belly fat or gas, no?
  36. Hi Chirs I am 45 and hitting Gym for last 6 month. I am with normal diet plan. Now I want to get into WHEY. I had a problem of high URIC acid level 2 years back with couple of Gout attack. I am 5.6 inch 72 KG and 45 years. Still have a lot of fats around my belly. I want to go for a shaped body with a good arm and chest not very huge body. Please guide me on which protein I should take and the quantity and frequency.
  37. Hi Christian, I recently bought "Optimum Nutrition Serious Mass". Chocolate flavour. I had it only twice with the milk after my workout. But since then I m not feeling comfortable. I had to pee every few minutes and it burns sometimes. Right now I have stopped having that whey powder. Can u suggest a solution for this.
    • Cristian Cristian
      Could you try drinking quite a bit more? That is kind of a requirement when you take protein. Or maybe you are taking too much. There's only so much that our body can take, the rest gets eliminated when you pee
  38. Great post, Actually I also suffered from stomach bloating but I shifted from whey concentrate to isolate due to the less amount of lactose, If you really want to gain muscle then combination of whey protein with creatine as pre-workout is the best muscle building combination.
  39. Which is the best protiens for bulky muscles body please suggest me
  40. Hi, I have been drinking protein shake for about a year and a half with hopes of gaining weight. I go to the gym about 3 times a week but always drink my shake every day before the gym because after the gym i usually have dinner. I use to have a very flat stomach and now i have this is patch of fat right under my belly button that wont go away. I started eating clean and that did not help at all so i was starting to think that maybe it is the protein shake i have been drinking everyday. any suggestions?
  41. its great,,i owe one..
  42. My stomach is pooching out but it is the top portion of it....Do you know what would cause that? I was taking whey protein but now I have stop taking it for about 2 weeks. I want to start taking protein again but I am afraid to take protein again.