Cellucor D4 Thermal Shock Fat Burner Review - UltimateFatBurner.com

Cellucor D4 Thermal Shock Fat Burner Review

Cellucor’s D4 Thermal Shock fat burner claims to be able to…

  • Attack deep fat deposits
  • Skyrocket caloric burn
  • Provide explosive energy
  • Suppress appetite
  • Improve mental focus

Since the Cellucor brand has the reputation for selling higher-end, more costly—and allegedly—more effective products, we thought it was high time we took a closer look at one of their offerings, putting the ingredients profile under the microscope.

So, what’s in D4 Thermal Shock? Two capsules boast a 1,093 mg blend of the following 10 ingredients…

1. Amla Fruit Extract: Also known as Indian gooseberry, this is one of the ingredients that Cellucor claims to act as a “beta-2 adrenergic agonist” in their formula. This, thanks to one of its active compounds—”phyllemblin.”

Unfortunately I was unable to either confirm or deny this claim, despite some fairly serious digging. When conferring with our scientific and technical advisor Elissa about this ingredient, she forwarded me this document, noting…

“This “kinda-sorta” confirms this claim, although it’s vague about whether any human research has been done. But there are no clear references in this document, nor are there any relevant abstracts to be found in PubMed. So either this claim is based on unpublished research; research published in very obscure Asian journals; “in-house” stuff prepared by whatever company they sourced the ingredient from; or stuff published prior to – say – 1960 (it’s much harder to find older abstracts/papers online).”

For the record, Amla is an Ayurvedic treatment for asthma and cough, so it’s not impossible that it contains some sort of beta-adrenergic activity.

However, even if we assume that Cellucor is right about phyllemblin being a potent beta-2 adrenergic agonist, we are still faced with a couple of problems…

  • How much phyllemblin is actually in the Amla extract?
  • Is it orally active?
  • Is the Amla extract standardized for phyllemblin?
  • Is it provided in an amount sufficient to produce the desired effects?

The onus is on Cellucor to address every one of these issues, and to date, they have not done so.

2. Caffeine: This ingredient has a well established record as a mild thermogenic, and does deliver mild weight loss results (see Am J Clin Nutr. 1989 Jan;49(1):44-50, Am J Clin Nutr. 1980 May;33(5):989-97). As such, it’s an ingredient common to the majority of fat burners on the market. And of course, caffeine cheaply and effectively addresses the most common complaint of dieters; lack of energy.

However, D4 Thermal Shock contains a TON of caffeine—290 mg per two capsule serving. That’s the equivalent to three cups of coffee’s worth! As such, this is a product that is going to give you one heck of a boost. If you have a sensitivity to caffeine and/or stimulants you will probably want to start with 1 capsule 2 times per day to assess your tolerance to this product.

3. White willow bark: In the old days, white willow bark was used as the herbal form of salicin, and comprised the third element of the good old ephedra / caffeine / aspirin stack. In ephedra-free fat burners like this one, there is no evidence it offers any benefit, short of the anti-inflammatory effects inherent to salicin.

4. Octopamine HCL: This is the second ingredient touted by Cellucor to act as a beta-2 adrenergic agonist. Just for fun, I’m going to pull the definition for this directly from our glossary

“A biogenic amine and constituent of Citrus aurantium (bitter orange). Octopamine is promoted as a fat loss agent, although there is only limited animal (and NO human) data to support this. Any effects on fat loss are likely to be weak, as its oral bioavailability is low.

5. Yohimbine: The standardized extract of the bark of the African Yohimbe tree, there is some data showing yohimbine is a somewhat effective weight loss supplement (see Isr J Med Sci. 1991 Oct;27(10):550-6) likely because of its action as an alpha 2-receptor antagonist. Evidence also validates its “lipid-mobilizing action.”

6. Evodiamine: A compound derived from the Chinese fruit Evodia Rutaecarpa. It’s claimed to burn fat by increasing the body’s production of heat, as well as reducing the body’s ability to store fat.

Although a preliminary animal study shows promising results, to date there’s no evidence showing evodiamine works in people.

7. Sclareolide: A compound isolated from clary sage extract. Theoretically, sclareolide is a cAMP stimulator (as is forskohlin). cAMP is what is called a “second messenger.” In other words, this compound is required to “spark” many intracellular processes. This can give rise to various “total-body” effects as raised thyroid hormone levels and increased fat burning. While there is some evidence that forskohlin exhibits modest weight loss effects, no such evidence exists to validate such a claim for sclareolide.

The final  ingredients are included to address the “improve mental focus” claim…

8. Passion Flower Extract: This herb demonstrates a mild sedative effect.

9. N-Acetyl-L-Tyrosine: An amino acid which happens to be the precursor of several important neurotransmitters (l-dopa, dopamine, norepinephrine, and epinephrine) which are important contributors to mood, cognitive performance, as well as combating stress. And yes, there is evidence that l-tyrosine has a positive effect on mood (see full tyrosine review for accompanying clinical references) and cognitive performance.

Unfortunately, these results were obtained with dosages that vastly exceed what is present in this formula. For example this study (which showed an improvement in cognitive function) was performed with 100 mg/kg tyrosine.

To put that in perspective a 200 lbs. man would need to take about 9 grams, or 9000 mg of tyrosine to obtain this effect.

If D4 Thermal Shock contained nothing but tyrosine, it would take 4 days worth of capsules (at the full 4 caps/day dose) to deliver an effective dose.

Although the “acetyl” version of tyrosine may (or may not) be somewhat more effective, there’s certainly no reason to believe this ingredient serves nothing more than label dressing in this formula.

So there you have it—Cellucor’s D4 Themal Shock.

As you can see, there are a few problems with this formula. For one, several of these ingredients appear to be included on the basis of mere speculation.

Others have little or only animal based clinical evidence to validate their effectiveness, and others… well, they’re simply ordinary ingredients you can readily find in much cheaper products. You might enjoy the “blast” of energy D4 Thermal Shock Delivers, but you really don’t need to spend $45 / bottle for it.

In my opinion, when you’re paying that much for a month’s worth of product, you have every right to expect Cellucor to “step up” with more than simple generalities and advertising “spiel”. Cellucor needs to provide some evidence that highly touted ingredients like “emblic myrobalan extract” actually work as described.

That said, I’d love to hear from any of you who have used this product. What did you think? How did it work for you? Use the link below to leave your comments, and read existing user reviews…

Author: Paul

Paul Crane is the founder of UltimateFatBurner.com. His passions include supplements, working out, motorcycles, guitars... and of course, his German Shepherd dogs.


  1. I have been on this product for 3 weeks now and have seen the same results I would if I were doing diet and exercise alone with no weight loss supplement. I do not recommend this product to anyone.

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  2. I am pretty knowledgeable on exercise as i have a degree in Exercise Science. As ive gotten older though some of the simple principles have become less and less effective. However, after starting this product and taking care to see that my diet and workout regimen are on point, i really saw the weight come off. I only needed to lose about 10 lbs and i literally lost that in 2.5 weeks.

    Sometimes i felt bad on it but i just took it easy and i was ok.

    My conclusion is if you take diet and workout seriously, this product is a great tool for your weightloss arsenal.

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  3. I took D4 for three weeks. I am in fairly good shape but needed to be bounced back to my toned physique ~ time/intensity of recent workouts has allowed for muscle atrophy plus poorer diet has resulted in some weigh gain. I took the one pill twice a day and felt nothing. Even cut out my one cup of coffee a day to make sure I didn’t get to jazzed up. Nothing! Increased to two pills twice a day. Still nothing. Honestly, if I didn’t know better, I would guess these are sugar pills. No change in appetite, energy, weight gain or loss. I really wonder if this is made for someone else ~ someone heavier than me, male? I am returning the pills tomorrow.

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  4. Hello, i run about 15 miles a week and I’m trying to loose about ten pounds.

    Cellucor is packaged in a clever aluminum can with nice colors. You would think it works or the company spent a lot of money. I did very little research before I bought the pill.

    I started with the one pill in the morning and then one in the afternoon. I definitely feel the caffeine working all day. I also notice the appetite suppressant working. In these two days i have noticed about one pound drop from my weight, or this could be water weight. Good luck and hope this helps.

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  5. Today is my first day on D4. I am more energetic and am not hungry. Years ago I took Metabolife and had excellent results, until everything was reformulated…. All I ate today was a buttered roll with my coffee, plain boiled zucchini and a banana. It is now 2:30 p.m. Let’s see what happens at dinner time.

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  6. I’ve been taking this for about a month and I really like it – not as a weight loss supplement but as an energy supplement and appetite suppressant.

    It helps me burn through my workouts and kills my appetite so I don’t crave the sweets and carbs. There would be absolutely no point in taking this if I wasn’t going to work out and eat right, but it is a nice tool to use in combination with exersize and diet.

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  7. This is my second day taking cellucor kit. Which includes the D4, T7, and WS1 extreme. I weighed in at 264 yesterday and today I’m at 258 lbs. It’s crazy how much i lost in one day I just hope that I do not rebound from this product.

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  8. I took D4 Thermoshock last summer at the recomendation of a gnc employee. Now I know you are thinking, what a mistake, right? Well don’t. On June 5th 2010 I, a 6’1″ 22 year old male weighed in at 245lbs. By the 1st week of july, I had dropped weight to 210 lbs. 35 lbs of weight loss in 4 weeks of D4, diet, and exercise.

    The first 3 days, I took 1 pill twice daily at 8 am and 8pm, bumping it up to 2 pills twice a day at the same times by day 4. I could feel my core body temperature raised, increased mental focus, better pumps during workouts, outstanding energy, and I was sweating like a pig during my workouts.

    Keep in mind, however, I was drinking about 3-4 liters of water per day so the weight I was losing was not water weight at all. I am also not a newbe to stimulants such as caffeine, and I used to take stackers when they still contained ephedra (still the most productive weight loss agent I’ve ever taken).

    After I was done with the bottle and into the 2nd bottle, I got sick. Fever, chills, stomach cramps, nausea, headaches. These symptoms lasted three days, worsening severely each day until I decided to stop taking D4 after 6 consecutive weeks of using the product, and in 2 days all the symptoms disappeared.

    Looking back now, I probably wasn’t eating enough the last 2 of the 6 weeks and that may have contributed to the illnesses, duh. Any way, its January now and I’ve spent the last 6 months ingesting protein and awesome workouts and I will be starting my next round of D4 the first week of February, ill post back in march with my results.

    Editor’s comments: Joe, the only to ensure you’re not losing water weight is to track your body fat percentage – regardless of water consumption.

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  9. I really like this product it really helped me with my appetite. I barely eat which is kinda unusual for me cuz I love food.

    But it needs to come to an end. I am 5’4” and I weigh in at 180 lbs. After literally 3 days i have already lost 3 pounds so that is about a pound a day and also I am exercising about one and half hours a day and I am on a low carb diet. Without the fat burner it probably wouldn’t have worked as well. I recommend this to everyone out there 🙂

    Good luck!

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  10. I have been taking D4 Thermal Shock for a few days, it really suppresses my appetite but it also makes me very nervous and jumpy. I just don’t like that feeling.

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  11. As a trainer I wouldn’t recommend this product. GNC reps recommend it because it is more expensive than the other products that are discounted. I was on prometalean hardcore for 4 months. I was taking 2 pills 3 times a day for a total of 6 pills. I switched to D4 for the heck of it and it hasn’t done much. I think the reccomended dosage is not enough but then again coming from 6 pills and going to 2 probably has something to do with it. I will admit it DOES help me not get hungry but as for the fat burn I am looking for I get more put of other pills especially hydroxycut pro which is half the price of D4. As for all my clients that I train I would not recommend this pill.

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  12. I have used this for several months. It really causes a feeling of fuzziness every time I take it and also gives some intestinal distress. While I think it may have helped me to maintain a level of leanness, I think the same effect would have been achieved by limiting carbs somewhat. Given the cost (EXPENSIVE) and the negative effects that I had from taking it (heart palpitations, fuzziness etc.) I don’t recommend it.

    I am a long-time bodybuilder and weightlifter.

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  13. After these three days I’ve lost 1 lb so far, so as long as it keeps doing that I’ll be straight and health =). Appetite does go away, sweet. I guess the only downside I have had is in the afternoon, I have felt the need for a short nap, not that bad. I need 20 lbs gone.. it’s going! Bye bye

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  14. Well you know I figured why this product works for some people and some do not. this product works real well when you drink a lot of water. and when you do not I barely feel the effect. This product is great to complement with diet an exercise. But remember to drink plenty of water.

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  15. I started noticing a huge difference in weight lose…. I workout 6 days, and 4-5 days of at least an hour cardio. This product does require stay well dehydrated, I drink about 8oz of water per hour. In addition, I am health conscious. I don’t eat fast food, no soda or artificial sweetners. If you not eating right you are wasting your money. This is not a magic pill, its a supplement that is suppose to work synergistically with your already healthy habits. My wife has notice my ever becoming tone and chisel appearance. I went from 22% b.f. to 12%, my goal is 8-9%. I haven’t looked this great ever!!!

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  16. I’m 25yrs old female, 5’2″ ,and I weighed 165 lbs. I started taking these pills two days ago and worked out for an hour or two. I also used the sauna for a half hour to fourty five minutes. I have lost five lbs. so far. I’m hoping to weigh in at 130 or 140. Or maybe below that. I don’t want to feel sick from losing too much weight.

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  17. I am 6’1″ male 215lbs. I wanted to cut out the extra weight i have always been carrying around my stomach. I have started eating light meals morning noon and night, mostly grilled chicken. I would say my caloric intake is around 1200 a day. I run 3.8 miles 5 times a week and do regular exercise 3 days a week. I went to GNC to see if I could buy something to help with the weight loss, They recommended T7 Extreme and D4 Thermal Shock. I have used the pills for 3 days and feel my appetite suppressed, and more energy. I have lost 6 lbs in the 3 days I have been taking them. I will repost once my month is complete.

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  18. This was recommended by a GNC employee, and so far its working great. I work out 5 days a week (3 days of weight lifting) and i have lost 6 lbs already, without any dieting, but just cardio and lifting. Also, my mental focus has improved a lot since ive taken these. I do recommend this to athletes who are trying to lose weight.

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  19. I started this a few hours ago and WOW am I feeling weird. Very energetic and I guess jumpy feeling. Kinda not nice. Is this normal? Will it go away with continued use, or my body gets used to it? I am 5’4 120 lbs and just want that bit of help with the toning of my body. I just hope the people around me don’t wonder what is wrong with me, I just feel like I am weird now… I just hope it works!!

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  20. Prudence, you are not alone. I’m on day 1 of the D4 Thermal Shock and it’s almost like an out-of-body experience. I feel really weird. Light-headed, dizzy, slightly nauseated. Definitely jittery. It’s time for my second dose but I’m not taking it as I still feel weird from this a.m. Upside: I haven’t even wanted to look at food today. Downside: I kinda feel like crap. Gonna try it for a few more days to see if I get used to it but if I keep feeling this loopy it’s going back. Let me know how you’re doing on it ok??

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  21. The fist day I took the pills I felt weird but now it’s been 5 days and I am focused. I haven’t sleep well for few months and now I am sleeping like a baby. I take it with food and I drink water all day. So far I feel good. I hope to see results in my body soon.

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  22. I just took my first pill but I ate something lite before. I have not started to exercise yet but I am very active in Real Estate and burn lots of calories. After I read all the reviews I hope I will be ok because I have to show houses. I will follow up.

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  23. I have just started taking D4 and I definitely feel the rush of the caffeine. I haven’t exercised in a while due to injury, but I do a lot of running around at work. I was just wondering if you see results from D4 with out exercised, however I do eat healthy and don’t drink soda. Will i still experience the loss of fat?

    Editor’s comments: Joe, weight loss is simple mathematics; if you consume less calories than you require you will lose weight, if you eat more, you will gain. Products like this may suppress your appetite a bit so you eat less – if it so happens that you eat less than you require, you will lose weight regardless of exercise.

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  24. I’ve been taking D4 for one week now and ive lost 7 pounds in this week, but I have been having severe stomach pains. I was wondering it that was experienced by anyone else? I didnt get that light-headedness, or ‘funny’ feeling that others did, but the pains are kind of concerning me. i toss and turn at night because i cant sleep on my stomach without having pain. I loved the results and want to continue but not sure if i should

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  25. I had purchased the stacked set of D4, T7, and MS5. I understand with everyone explaining a strange out of body, jumpy, or funny/awkward feeling. It starts slowing down and then stops all together after some time taking the supplements. It works amazing and unless you stop exercising, eat like complete crap, and drink sugar drinks after youre done with the cycle, the weight DOES NOT come back. I mean you have to completely slack off for it to start creeping back. Water is absolutely necessary and i cannot stress it enough. 1-1.5 gal a day is plenty; keep in mind there is water in food you eat too. As a last piece of advice: the more intense the workout (i.e. crossfit) and the better the diet (paleo, zone etc.) the faster the results.

    I took this product for 3 months straight and am about to start another cycle.

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  26. I started D4 Thermal shock 6 weeks ago and let me tell you how much this product worked for me. I was doing weight watchers and dropped 10 lbs in a month, and then i started to plateau, so I started taking the D4 that a GNC employee suggested and Ive lost another 15 lbs in about 5 weeks!! It completely suppresses my appetite so I really only eat when Im hungry. I started my weightloss kick 9 weeks ago at 201 lbs, Im now under 175 lbs!! I love the product!!

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  27. Ok so I am on day three of D4. I LOVE it, It works great with LOTS of water..did I say LOTS of water..because you really should be drinking LOTS of water with this! I am a very active person and have a goal of 15 lbs to drop. I work out 4 days a week and coach volleyball the other three days a week I will see if this gives me the push that I am looking for. 🙂

    I have lost 1.8 lbs in the last three days!!! 🙂

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  28. I just started D4 yesterday at lunch. I went to GNC to get something to help me with my weight. I am going through menopause so it has been REALLY hard for me to lose weight. The GNC employee suggested I take it before I ate my lunch and I did and recommended I drink LOTS of water and I am. I was not hungry for dinner two lbs lighter this morning. I took my morning dosage and age my breakfast. I feel good and not jittery, so I am wondering if those that say they feel strange are not drinking and or eating enough. I am looking forward to GREAT results.

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  29. Well I have debating on buying this product I have a patient that lost weight with D4 and looks very good. I made the decision to buy it today will see if it works for me. The gentleman at GNC was very helfull ….

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  30. I have been taking this for 6 weeks now every weekday 2 to 3 times a daily and I weighted in today down 33 lbs. I have been running on the weekends (last weekend I covered 15 miles), consuming a smoothie for breakfast, a slim fast for lunch and something reasonable for dinner like a salad or other low fat meal for all the weekdays and eating what ever I want on the weekends. I can not tell a whole lot of anything after I take this product but this plan is working for me currently. Hope this helps…

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  31. Purchased the kit yesterday (D4, T7 & L2)under the recommedation from the GNC employee that has been helping me with my weight loss. He had stirred me to Oxy Elite Pro and that worked wonders, really love that product.

    I used to be 315 lbs and in 7 mths I am now 210lbs. Keep in mind I eat no more than 800calories a day, no splurge days and I work out 5days a week for about 2hrs inclusive of pilates, yoga, booth camp and swimming. However, in the last 3weeks I am barely loosing weight about 2 lbs a week.

    I wanted to find out more about this product before actually taking it and I am thinking not. I really do not want to feel jittery or nauseated as I am a corporate lawyer and need to be professional at all times at work. I do drink about a gallon of water a day and I do eat sensible (no fast food, 8 servings of fruit and vegetable a day and protein). I am thinking this might not be the right product for me.

    Anyone recently used the kit and it worked for them?


    Editor’s comments: Ever consider taking in a few more calories, Debbie? At a caloric rate that low, we’ve no doubt your metabolism has slowed to a crawl. We’d be willing to bet adding an extra 400 – 700 calories a day might be the best thing you can do for your success.

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  32. I have been using D4 thermals shock for the last 3 weeks along with optimum nutrition hydro whey and amino energy. I work out about 4 days a week with weights and cardio. The first week I took purely D4 and did see a good result dropping from 225lbs to 221 lbs , My energy was good no jitters like I got with hydroxycut hardcore. 2nd and third week I added in the ON supplements, mixed with a low carb high protein diet and dropped to 208 lbs. Results vary from person to person and you can’t rely purely on D4 Pills you need to put the work in too.

    It works for me 🙂

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  33. Hi . I m 5 7′ and I weight around 72kg I purchased d4 thermal shock last week . I was not doing any exercise from 2 or 3 week so I want to kn0w first I should I start an exercise routine and then start taking d4 or start it straight away?

    Also I would like to know – my coach is sayin come to gym mon to sat and sunday rest and also to take 2 capsule mon to sat and take only one capsule on sunday . But on the bottle or jar its written 2 capsule daily so we have to take 2 capsules on sunday and on days we don’t do exercise that day also 2 capsule should be taken
    I really want to gain max. Effect from this d4
    kindly recommend the dose . And clear my doubt

    Editor’s comments: Reducing the dose on a single day is unlikely to make a dramatic difference in the effectiveness of the product. And whether you want to start the product now or wait until you work out is largely a personal call.

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  34. On day two of the D4. I usually have an enery drink in the morning, but since starting the D4 yesterday, I decided to forego the energy drink. I have not noticed any increased energy for sure. In fact, I think the D4 is making me sleepy.

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  35. It hurts my stomach so bad! I have been following the instructions. The pain is terrible even if i had a good substantial meal before taking it. Such a waste of money.

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  36. First day using this product was woundering if this could be stacked with other pre-workout supp “ie” N.O Explode MRI Black Powder or N.A Vapor?

    Editor’s comments: It’s not a good idea to take them together – WAY too many stimulants. However, you could take a dose earlier in the day, and skip the second dose on the days you want to take a preworkout supplement.

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  37. Also I would like to know – my coach is sayin come to gym mon to sat and sunday rest and also to take 2 capsule mon to sat and take only one capsule on sunday . But on the bottle or jar its written 2 capsule daily so we have to take 2 capsules on sunday and on days we don’t do exercise that day also 2 capsule should be taken
    I really want to gain max. Effect from this d4
    kindly recommend the dose . And clear my doubt
    The main thing is I want is it safe and what do u recommend I dont want to compromise the effectiveness…….:)

    Editor’s comments: When in doubt, stick to the label instructions.

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  38. Well I have been taking d4 thermal shock from 25 days and my bottle will be finished in 4 or 5 days, can I switch over to oxy elite pro without giving any days gap since I have heard oxy elite pro is very good. Is it safe to switch fatburners without giving a month gap? Or I should stick with d4 thermal shock only and complete my 2 months cycle.

    D4 has shown me result ….. Very good 🙂

    Editor’s comments: We don’t see any reason why you can’t switch over.

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  39. Makes me sick! I can’t function. Makes me sick to my stomach, head spins, I get all shaky and sweaty also cold at the same time. Cramps and diarrhea included.
    Took me hours to come back to some sort of ‘normal’.

    I vote NO.

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  40. I have been using this product for a little over a month now, along with t7. The potential for weight loss was greatly increased although with the extreme summer time heat has made cardio much more diificult. The only bad side effects I have experienced were caffeine rushes, which were extremely mild… Bout like a 20 oz energy drink. And increased heart rate during moderate cardio (was to afraid to see what extreme cardio would do). …overall for weight loss I would recommend going with one of the many other leading products, and ordering from an online whole seller. Otherwise you will end up over paying by like 200 percent.

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  41. I just bought the d4 today and will start it tomorrow. i have limited time so i have to workout in the mornings, and need some input on when i wake up when should i take it eat and workout.

    So my question is when i wake up at 5 take it with multivitamin should i eat or what. An i have to leave by 6 to make it to work.

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