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Cellucor C4 Side-Effects

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cellucor c4 side effectsI’ve been on the Cellucor C4 Pre-Workout since my first post about it back in November. By no means have I been taking it 5 times a week since November, but I have been fairly steady with it. I am up to 2 and 3/4 scoops and would like to share some of the Pro’s as well as the side effects of Cellucor C4 for those that are wanting to learn more about it.

Recent Side-Effects

The first few times I took Cellucor C4, I experienced moderate itching on my face and some jitters. I started out with 2 scoops so I expected to feel something; in fact, if I didn’t have jitters or a bit of an itchy face, I would have been a bit disappointed.

But this morning, it was out of control. My face, legs, neck, and back were all itching and tingling like crazy before and while I was at the gym. I wasn’t super jittery while I was at the gym, but when I got home I could not keep my hands and arms still. I remember 1.M.R making my forehead itch, but never anything like what I experienced this morning. I have an early morning Math Class and I could barely take notes because my hands were shaking so much. It was pretty frustrating and very abnormal.

Possible Reasons for these Side-Effects

This is not my first time experiencing a great deal of shaking, tingling, and itching as a result of Pre-Workout. It’s happened frequent enough that I think I have a pretty good idea of why it happens when it does.


I get the jitters when:

  • I take more than the recommended serving
  • I don’t workout hard/long enough – running for long periods of time reduce the severity or overall chance of me getting the jitters
  • I do a lot of low-weight, high-rep training
  • Jitters are almost always felt post-workout; rarely before or during.

Itchy Face, Forehead, Neck, and Back

This is one of the most common pre-workout side-effects [for me, anyway]. I experience itchy face when:

  • I take more than the recommended serving
  • I take Pre Workout early in the morning or late at night
  • I don’t drink a lot of water

This morning, I took more than the recommended serving, took it early in the morning, and didn’t drink a lot of water during my workout. However, I ran for quite a while and did high-weight, low-rep training. So I would think those would balance it all out a little bit. But would that make sense? I honestly don’t know.

c4 side effects

Cellucor C4 Ingredients

Maybe pulling this pre workout apart a little bit will give us a better understanding as to why our bodies react the way they do when we take it. I’m not a genius on this sort of thing, but there’s nothing Wikipedia can’t handle.

You can see what Cellucor says about the ingredients of C4 on their C4 Extreme – Technical Data page. They have a cute little description of each ingredient which is [always] biased. So, I did a little digging around of my own and found Synephrine HCI to be the possible culprit for both the itching and the shaking.

Cellucor says:

“Synephrine is a potent adrenergic stimulator that augments energy levels and ATP synthesis. Synephrine, although milder, is structurally similar to Ephedra. The compound enhances adrenaline stimulation and promotes weight loss by amplifying fat burning, metabolism, and thermogenesis.”

Structurally similar to Ephedra, huh? What is Ephedra??

Wikipedia says:

“Ephedra has also been used for weight loss, sometimes in combination with aspirin and caffeine [Exactly like Cellucor and other Pre-Workouts]. Some studies have shown that ephedra, when taken in a regulated and supervised environment, is effective for marginal short-term weight loss (0.9kg/month more than the placebo), although it is unclear whether such weight loss is maintained.

However, several reports have documented the large number of adverse events attributable to unregulated ephedra supplements.
Side effects of ephedra may include severe skin reactions, irritability, nervousness, dizziness, trembling, headache, insomnia, profuse perspiration, dehydration, itchy scalp and skin, vomiting, hyperthermia, irregular heartbeat, seizures, heart attack, stroke, or death.”

Obviously [or, I hope], Synephrine HCI is not nearly as dangerous as Ephedra, but it sure would explain why Cellucor C4 makes me itch and that’s good enough for me.

Still Considering Cellucor C4?

Don’t get me wrong, Cellucor C4 is the best thing since Jack3d. I love that it doesn’t make me crash and the pumps really are terrific. There are Cellucor C4 Extreme reviews all over place, including this video that I found to be very helpful. Enjoy!

  • Chris

    Check out the ingredient Beta Alanine. Thats more than likley the ingredient thats contributing the itchy feeling. Cellucor has the ingredient at an effective dose for reducing delayed onset muscle soreness, and that’s why you may feel it more than with other products. Its by no mean harmful, but it does have a good tingly effect.

    • Nate Armstrong

      Very interesting. And I’ll bet you’re spot on.

      Thanks for stopping by Chris!

    • Guest

      Notice “chris” doesnt disclaim that synephrine HCL is dangerous. IT IS. Its banned in Canada. I know there is some Doctor on youtube saying its harmless but seriously this guy is a shady crackpot that has been clearly paid off by some company having him do their PR. The whole beta alanine hype is a smoke screen with this product. Yes Beta Alanine is exciting right now but you have to be retarted if you think that beta alanine is the reason why you are feeling pumped during your workouts or why you feel like your energy levels are through the roof. This stuff is a cousin to ephedra, enough said. You know it is really important to do your homework before buying in to supplements. Its virtually an unregulated industry and although products like c4 will do their job, it often comes at a hefty price, which by the way you will be paying back at some point down the road, which the piper will always come to collect.

      • Newbie

        So what preworkout would you recomend?? what is the safest product out there?

        • Jshyperrun

          a cup o joe

        • Guest

          Let’s put it this way, there are none. No matter what supplement you are using you are circumventing the bodies’ normal methods. Therefore you will at some point receive some negative effects. How about we take more of a route of Bo Jackson?

        • Icebreakersaau


      • Dieges

        What is “retarted”? I found “retarded” in the dictionary, so the whole rant above becomes suspect due to the fact that (1) he can’t spell and (2) he is misusing the word.

        • Dbenoit64

          okay substitute crazy for retarded dumbass… everything he says is right on the money. the potential damage can be doing to your internal organs from taking these supplements is not worth the pump in my opinion…

  • yashi

    i got this as a sample from buying protein i used it and nothing happend to me and im 14

    • Doyeli

      because your 14

    • Stove29

      lol im 14 and it works great, im cutting down on it thoug

      • TrainCanada

        you shouldnt be taking any pre workout c4 or otherwise at 14.

        • guest

          i’m not arguing, i’m just wondering why a 14 year old shouldnt be taking any perworkout. Is it bad for you? and speaking of c-4 speically, is it bad for you at 14 and what side effects worsen if your younger?

          • Mr-DJ

            Teenagers’ bodies are still in the growth and development process. When you interrupt it with these chemicals, you alter that process. Some things stop because you’ve confused the system, and may not re-start – so you’ve caused permanent damage. Those things will haunt you then for the rest of your life. There’s a reason it says: Over 18. And even then you need to be careful. You may be destined for a beautiful body naturally anyway, but once you start messing with it, you may regret it. Be careful, discuss with your doctor so he knows what he needs to watching out for, such as signs of liver / kidney damage, and how often.

          • Micheal Griffith

            I agree, as a young man everyone wants to look like Arnold, but the long terms effects of the bodybuilding field is sad. So many people that lift weights and don’t have good form leading to injuries in the gym. When you are young like that, your body is still changing chemically and when you put these kinds of foreign substances in your body at the same time, it is a recipe for disaster. It may feel good taking this stuff, but take it from me, I took many supplements from Whey protein, Amino Acid in pill form, creatine Monohydrate, C4, Jacked 3d, ETC, I also have lifted weights the natural way, guess what, with proper sleep and diet, I had the same strength and stamina taking no supplements what so ever, the supplement industry is a multi-billion dollar industry that isn’t FDA approved. Ask any doctor if he recommends you taking these supplements and you will get a straight up no.Good luck young man.

      • kaleb w

        i am almost 16 and from last year my bench went up 110 lbs and i am at 290lbs for my max bench. c4 works but i do feel some irritation to my kidneys so i try to drink water so i pee every ten mins to flush them out

  • Corey S.

    I use c4 five days a week. It’s an awesome performance boost. You retain focus and consistent eenergy all day. I workout everyday, I’m 21, 175lbs of pure cut. The secret is pay attention to your form and don’t use ridiculous amounts of weight, its unnecessary and damaging.

  • Ericfolks

    Your probably sensitive to the niacin. Taking straight niacin will cause red flushing of the skin and restsless itchy feeling all over the body.

  • Corey S.

    C4 is a decent product and I’ve done my research about it. Honestly I couldn’t find much about the long term effects, and the short term effects are as stated. Yes, you’ll see gains all the way around. Yes, you’ll have energy like you just drank 52 red bulls. Yes, you’ll feel tingly. Remember though, these products aren’t intended for an obese human to magically get skinny and ripped. That’s how 80% of these of heart attack cases happen. Also, in combination with other pre-workouts is just stupidity, that’s a way to jack your chances of heart failure. In conclusion, I use this product usually 5 days a week. I’m male, 21yrs old, 176lbs, I take only one scoop and attend the gym everyday. Point being if you want to use these products, for your own safety please do you’re research and decide if its going to be beneficial for you and if you’re physically capable of handling c4.
    **Drink water**
    **Stay Active**

  • Matt

    Unless you are 300 pounds and can bench twice that I would never recommend taking two or more scoops. I’m 170 and I never take more than a scoop before I workout and it has the same effect. Taking more wont make you work out better.

    • Anonymous

      I take 4 scoops a day before workout and I usually do intense speed and endurance training for around 3 hours of work out with a few water breaks in-between it is important to just match how much your are taking with the kind of workout you plan on doing honestly I couldn’t tell any thing with just one scoop and if you get the balance right you should have minimal side effects.

  • Masonm7497

    At this moment on my way to school, im experiencing the itching feeling all around my face, ears and arms. I googled the side effects of c4 to make sure i wasnt going insane. Lol. Thanks for the info.

  • Lrm710

    You might also be having an allergic reaction/mild hives hence the itching sensation. I’m highly susceptible to hives and broke out all over my face when I took another similar “fat burner” type product.

  • R Gilmore87

    acg3…. the end

  • Acs1224

    Don’t know you, bud. But there’s lost of evidence that synephrine is pretty nasty stuff. Am sure you can achieve your goals without it while maintaining your health. See:

    • WTF

      Thanks for the info. I have taken C4 for some time but recently stopped due to an unrelated health issue or so I think. I found that the best thing about C4 was the B12, C, NO and of course water. I also found that outside of the initial hyper rush, just water before, during and after the workout does just as good. B12 and C at breakfast. N.O. need to do more research.

  • Abtin Kalhor

    Hi I’m 16 years old my name is abtin and I’ve been using c4 kinda alot. I take 2 scoops of watermelon everyday plus creatine too before I work out. For the last 2 weeks I’ve been not able to sleep and I feel like things are crawling all over me at night and sometimes in the day. I’ve stopped taking both c4 and the creatine for 4 days now how much longer till I return back to normal?!?!?!?! PLEASE HELP

    • Micheal Griffith

      Stop taking it Period! This shit is made by people that dont have degrees. You will end up a Fiend, you are better off just taking natrual creatine.

  • Austin

    I have been taking C4 for about one month. I’m 17 years old and I take it about 5 times a week at the most. I do get a tingly sensation, but never feel itchy. I have tried other products and this is the best out of them all. 10/10 (side note) I am not a paid actor, because I do not believe they hire 17 year old people to make up lies about there product.

  • Louis

    Hi thanks for posting this. Yes I take 2 scoops pretty much 6 days a week and I feel it hi too. And the worst side effect with c4 is I feel weak and shaking during the ret if th day. I train in the morning. And eat a bowl of oats. And the rat of the day I feel very weak and shaking and my heat still pumps very fast. Does this happen to anyone else???

  • kaleb w


  • Tanner

    You’ll be alright. Even though you may not be as effecient, try to workout a week or 2 on 1/2 or less of your current dosage. Most of the pre’s recommend cycling off of them anyways, but easier said than done. Taking your amount of dosage, generally is going to make it somewhat difficult to fall asleep right away, depending on what time you worked out, how hard, etc.. Also, make sure to eat before you workout also. I’m not saying a large meal right before, but having some texture in your stomach will keep you from getting too “cracked” out, and keep a good pump without the week / jittery feeling you seemed to explain. I’ve been using pre for about 3 years now, and my favorite to date is c4 with White flood. White flood has a little more stimulant, but c4 delivers better pumps. Half of each seems to give me a good workout without the crash.
    Good luck!

  • Rachel

    It’s the niacin that makes your skin crawl. That’s why sometimes you itch.

  • Lee

    The itching came from the niacin… it has 30mg of niacin in it. Niacin is a peripheral dilator which will cause the face, back, hands, legs, and arms to itch, and even turn red. 30mg of Niacin is a high dose being that most supplements measure Niacin in Micrograms and not Milligrams like Cellucor C4 is measured… so you were taking around 30,000 Micrograms of niacin, and that is more than enough to cause ANYONE to have a niacin flush, which is what your experience. The flush is safe and actually healthy for you. But remember, many niacin containing supplements will have low doses so as not to cause this “flushing” sensation. When you experience this flush you can also experience a lack of oxygen at first and feel very panicked.

    I would recommend you take this product about an hour to an hour and a half after a meal and 1 hour prior to a workout to keep down on the niacin reactivity. You should feel less “jittery” then, and not experience the flush. Hope this helps!

  • ikepono

    trying C4 for the 1st time this week. i have tried JACK3D and other similar products before. They all have the same problem, caking. i live in a humid area and the product “cakes” and slowly turns into a gooish paste! This makes it hard to measure. one “caked” serving could actually be 2 servings since it’s compressed.
    i am getting super pumps during work out but feel lathargic post workout. thanks for posting the above article since it helps explain that an effort to have a good workout is crucial to keep the “jitters” away.
    i have not experienced “jitters” but i do have a high tolerance. I think this type of product should only be sold to Adults.

  • CTD

    I brought some C4 from GNC and the guy there told me all about the product. He also told me the side effects, saying that you should only use 1/2 to 1 scoops and only when you need a boost, to tired to work out that day or burnt out from a previously work out. Not to over do it maybe us it twice a week! He told me most people who work out are already full of energy. C4 is just for a emergency boost.

  • Bigjon

    i took C4 cellucor for about 3 weeks now…my first week and a half i felt pumped, got the whole itching effect and extra boost of energy. in that amount of time i went from 1 scoop to 2 scoops….then i went on christmas break for 10 days and was off the stuff, i come back & start working out again using 2 scoops of C4 Cellucore pre workout 30minutes before my workout as usual. Beginning my 1 Mile run i start to feel un focused and very dizzy, i keep on running anyways. i worked out twice as hard because im thinking maybe bein off c4 for 10 days and jumpin right back into 2 scoops my first day back was a bad idea, after my workout that night i still felt very un focused, also my heart was feeling like there was pressure on it, didnt hurt but it sure did bug me….so i found myself here on this blog reading more about it. & i would have to agree with much of what is being said here i did feel dizzy, my heart felt like there was pressure on it, i couldn’t sleep at all.
    ive been doing high intensity training for 3 years on and off (crossfit). This is the first pre-workout i have ever taken, i have not used any anabolic muscle gainers. so in my opinion the best energy comes from non-processed foods, you wont feel that pump or anything but eating healthy & working out consistently is definitely healthier. People tend to rely on suppliments such as C4 & Creatine as their way out of obesity or staying fit. BIG MISTAKE. bad habbits are not changed, obesity is not a quick fix, you must earn your body & all these Muscle enhancers & Pre Workouts are an east way out but at a large cost of your health. Be Natural !

  • John

    Having a reaction as we speak. Its extremely painful,

  • Nick

    I just took 2 scoops of c4 today before my workout today. I did the usual clean, bench, squat, then a little running. I have only used this a few times. I also took my shake after my workout like usual. But today the whole car ride home and right now after a long shower and dinner I just feel dizzy and basically like s***. I got the usual itching during my lift but I haven’t ever felt like this after a lift. Is it from the c4? Is it just from my protein shake? Or am I just over reacting?

    • Devin

      I know it’s a late response but it’s for the people who also come across this question. I’m 16 and I take 1.5 scoops of C4, 2 scoops of my protein (60mg) and around 30mg creating everyday and I do basically the same workout as you daily. I almost always feel dizzy and have blurred vision for a few hours after my workout and the protein makes me feel like ass. I’m gonna have to say it’s the protein shake. Maybe cut down on the amount of protein you take in and you should be solid.

  • angel

    I just read a text that makes it sound like my teen and his friends may be snorting this stuff to help them preform better in sports. I’m pretty freaked out. Is this something anyone else has head of?

  • Joel Caltavuturo

    has anyone else had trouble sleeping when using C4? this is my second week using it, and i feel great after my workouts, but i have difficulty trying to fall asleep. i try to go to bed early, around 10pm, but i really dont end up falling asleep til about 3 or 4…anone else have this issue?

    • Wesley

      Same issue. I don’t use electronics or anything while I lay in bed. I’m pretty sure the c4 just keeps me up. I don’t see why though. I’m a recovering speed freak and could sleep on anything.

    • Hugo

      Man I usally got to the gym around 10pm and took 1 scoop of c4 at 9:30 felt great during workout but man when I got home I wasn’t able to sleep to this moment I’m still up doing research . Turns out I can’t sleep and it’s 4:00 am already

  • JessK

    If anyone is interested in all natural products please send me a message!

  • Nick

    I’ve used niacin as a detox to clean my system out so I could piss clean and niacin a definitely will make you itch.

  • lindsay

    I had the side effects now for 11 hours plus the insomnia (clearly) but from all the doctors I”ve seen today they said its different for everyone. they arent nearly as bad now as when they started though felt my body was on fire like painful tingling fire.

  • Kim

    I took C4 strawberry margarita yesterday for the first time ever. At first within the first 20 mins it was a great energy booster but then after a couple of minutes I felt my lungs start to get really heavy and a shortness of breathe ,extreme dizziness, and my heart rate was at its max. I ended up at the hospital with an asthma attack and an allergic reaction due to the C4. I shall never use this product again. Please when using this product be careful.

  • Jake

    I am 16 and ive been using c4 for about a week and a half i take 2 scoops before my workout and its honestly the best thing ive ever taken protein just makes me gain weight this burns fat and builds muscle i do tingle and itch but i get insane pumps and i recover so fast its crazy i can work out for two hours(my normal workout length) and still not be tired or sore, i love it

  • Matt

    I know what u all mean by the itching and everything I weigh 200 and take 3 scoops the effects go by your workout it honestly goes away has you workout if ur still itching when ur done then u didn’t go hard enough you gotta work it out I have had the same things happen when I wldnt go hard and if ur not itching from the start or don’t tingle then ur preworkout doesn’t work I wait till that feelings comes to even touch a heavy set I walk until it happens and just like any pre workout ur body gets used to it u gotta quit for Atleast a month and then go back to it that means any pre workout or caffeine that’s if u wanna keep having the full effect when u take one

  • Nurse mom

    Told my son to stop this product after he had itching, flushed, numbness and tingling of arms and hands . Similar products have been banned by the FDA! I am a nurse, I have seen PT’s with heart damage from ephedra !

  • jakob

    Im 17 and it makes my bladder hurt. Why is that i only take a max of 2 scoops. I have no other side effect.

  • Maricel

    I take half a scoop and that lasts me perfectly through an hour of cardio and heavy (for me, anways) weight training.

  • John H. Louisville Ky.

    The itching and or flush feeling is definitely caused by the NIacin. Some people have a worse reaction to it than others. Niacin is essential in promoting good health. (Do your due diligence on the positive and negative effects of niacin. They make a flush free form of niacin if you determine it is what your body needs and perhaps what your body lacks, by doing your research. Best wishes, and always consult with your medical professional before working out. The insomnia you are experiencing could be based on your excitement over the results you will achieve in a very short time. Do not miss workouts, period. And do not use steroids.

  • eddi_e2003

    Hey guys just wondering why C4 warning says if you take medicines for ED you shouldn’t take this stuff. Anyone know the reason why?