This week, I obsessed over every aspect of the weight-loss drink Celsius, so we examined the ingredients, side effects, clinical research and quality of customer service. We scoured hundreds of consumer comments and reviews. We then refined and summarized to give you the info you need.
What is Celsius?
To start off with, Celsius is a weight-loss and energy drink that has green tea,  guarana seed extract, ginger root, B-vitamins and chromium. When you consume one per day, it will supposedly helps you increase energy. A benefit is you can consume it on the go.
The product, introduced in 2004, uses some natural ingredients, which is a good choice. You can buy the drink at retail stores, but you can’t order it from the official website. We like that there are some people who’ve had positive experiences and the company has been around a while, but read on…
Celsius Side Effects – “Feeling a Bit Shaky?”
The first concern we have involves Celsius side effects, which may include jitteriness and stomach concerns.  “Energy drinks contain stimulants, that’s often the nature of the formula,” said our Research Editor. “It’s how much is included that can mean the difference between a good punch and a jolt that doesn’t feel so positive.”
“Once I drank Celsius, I immediately felt jittery which I felt was odd,” said a consumer of Celsius ingredients.
“I was suffering headaches, muscle twitches and even a flutter in my chest,” reported another.
Side effects are different from one person to the next. According to one dieter, “I have no shaky after effects, no queasy stomach.” 
We also found one that said, “Tastes nice and does not make you jittery.”
Celsius Taste – “Not What Was Expected”
According to some customer comments, the taste of Celsius wasn’t right. Some commented that the beverage tasted flat. “To me it tasted flat and artificial and all around not good,” said a customer.
“This tastes nothing like mango or peach (not to us). I can’t even describe the taste,” explains a dieter.
“So nasty tasting had to dump the majority of the cans down the sink,” commented a user. 
Products like Celsius will always have some consumers who like them and some who don’t. One person who had a positive experience said, “It tasted kind of weird at first but I got used to it real quick and now I look forward to drinking them.”
Another shared, “It has a good taste and helps to boost your energy.”
Our research shows it takes just a small part of a weight-loss program, like side effects, to hamper chances of long-term success. If Celsius leaves dieters feeling jittery, they may not continue using the product.
The Science – “Clinical Evidence?”
There are links to clinical studies supporting certain claims made by Celsius. What interested us the most was the “Weight Loss Effect in Overweight Women” paper. This one doesn’t come with a link to the journal where it was published. Even better is the participants “reported to a training facility” on workout days. The average dieter doesn’t have access to this type of exercise routine. The science is lacking with Celsius and at DietSpotlight that’s what’s most important. If there’s no proof a product works, there’s no real reason to spend the money. Also: read our Leptigen Weight-Loss Kit review »
The Bottom Line – Does Celsius Work?
Well now, the verdict is in on Celsius, so what did we find? There are positives, including a few good customer comments and the fact that it has natural ingredients, but we have some reservations because the research performed was not realistic for the average dieter. We are also concerned about potential side effects and bad taste.
If you’d like to slim that waistline, we recommend going with a product that with ingredients backed by published clinical studies that aren’t there to make you feel worse for the wear.
Among the best products we’ve seen this year is our product called Leptigen. The formula consists of a four-ingredient blend, all clinically-tested with results often located in publications such as The American Journal of Clinical Nutrition and the Journal of Medicine.
Additionally, we’re so confident that you’ll love our supplement that we’re offering a Special Trial Offer, which is a great sign.
Previous Celsius Review (Updated August 25, 2014):
What You Should Know - CelsiusCelsius is an energy drink that claims to raise metabolism by up to 12% and boost energy levels for 3 hours with their natural, smooth blend of antioxidant rich ingredients, including Green Tea Extract, Biotin, Guarana Seed, and Calcium. Sold in popular store such as Kroger's and Walgreens, Celsius touts itself as a cheap, flavored drink that claims to keep dieters alert, focused, and slim by burning 100 calories per bottle. Though it does not claim to be a diet supplement, it does claim to be the perfect drink for boosting energy levels during the day. This flavored drink also contains caffeine which found in a study that drinking coffee can potentially lower your risk of liver cancer. Although a diet is the best way to boost the metabolism and stay alert, turning to an energy drink may help dieters when energy levels are running low. It is vitally important that they pick the right drink with provable benefits, however, and an affordable price tag. Celsius may deliver on some key points.
Ingredients in CelsiusAccording to Celsius, their drink contains Calcium, Chromium, Vitamin C, Vitamin B, Biotin, Riboflavin, Niacin, Guarana Seed, Green Tea Leaf Extract, and Ginger.
Product FeaturesCelsius focuses on including natural ingredients instead of synthetic ingredients, and some ingredients may legitimately boost energy levels. Green Tea Leaf Extract and Guarana Seed are both sources of caffeine, and the type of caffeine contained in both sources is scientifically-proven to be gentler than straight Caffeine. This type of caffeine stimulates the central nervous syndrome to halt fatigue and causes a less harmful "energy crash" when the effect wears off. Green Tea Extract also contains chemicals that stimulate the metabolism, and sipping two or more cups of this tea may result in increased metabolism. This may be the source of Celsius's claim that it may stimulate the metabolism. Celsius's other ingredients do not contain any provable dietary benefits, but it may provide nutritional benefits. Calcium is important in any diet and some studies show it may help dieters lose weight, but it is best digested from natural, organic forms, such as yogurt or milk. It does appear Celsius does contain some ingredients which may boost energy levels and the metabolism, but all sources have a better effect if taken in natural form. Green Tea tends to work the best in its natural form, for example, and its extract form is notably less effective.
- Contains Green Tea Extract, which may increase the metabolism in larger doses.
- Contains natural ingredients which do not have any major side effects.
- Ingredients have more potency in natural, non-extract form.
- Its main ingredients do not have any notable dietary benefits.
- Not intended for use as a diet supplement.
- May cause jitters and trouble concentrating. (See reader comments.)
Conclusion About CelsiusCelsius is a natural drink that claims to boost the metabolism and energy, and its ingredients may contain some of these properties. Depending on a diet drink to help boost these levels may become addictive, however, and obtaining these benefits from natural sources may offer stronger results.
Celsius Questions & Answers:
We looked at hundreds of user comments about Celsius to create this helpful FAQ.
What are the side effects of Celsius?
Celsius side effects according to customer comments, may include feeling jittery, heart palpitations, headaches, and nausea.
What is in Celsius?
Celsius ingredients include taurine , guarana, green tea, caffeine, glucuronolactone and ginger and chromium.
What is the active ingredient in Celsius?
The active ingredient in Celsius is the MetaPlus proprietary blend, containing taurine, guarana, green tea, caffeine, glucuronolactone and ginger.
Does Celsius work?
There are several positive aspects of Celsius, such as the natural ingredients, like green tea and caffeine . Unfortunately, the company does not offer any clinical research supporting the claims.
How much does a bottle of Celsius cost?
A bottle of Celsius costs about $2 each. You can also purchase a five-pack for $10.99 or a 24-pack for $29.98.
How do you take Celsius?
You take one Cels per day to boost energy. The company doesn’t offer specific recommendations.
Can I take Celsius if I have a health condition?
Women who are pregnant or nursing, those with health conditions, anyone taking prescription medications or people under 18 years of age should contact a healthcare professional prior to using energy drinks of any kind, including Celsius.
What do users like about Celsius?
Some users like one or more of the drink flavors offered by Celsius, while others felt a boost in their energy levels.
What do users NOT like about Celsius?
The taste of the Celsius drinks was often described in negative terms, making it one of the main reasons consumers stayed away from the products. Other reviewers felt the negative side effects were too much.
Who makes Celsius?
The makers of Celsius is Celsius Holdings.
How do I contact the Celsius customer service department?
You can contact the Celsius customer service department by sending correspondence to Celsius Holdings 2424 North Federal Highway Boca Raton, FL 33431, by using the feedback form on the official website or by calling 1-866-423-5748.
Can I contact Celsius through social media?
Will drinking Celsius make it difficult for me to sleep?
There are high levels of caffeine in the Celsius drinks so it is possible it will make it more difficult for some people to sleep. We read several reviews where people specifically said the drinks seemed to keep them awake at night.
Are the Celsius drinks carbonated?
Yes, some Celsius drinks are carbonated.
Where can I find Celsius?
You can order Celsius from online retailers such as Amazon, and it can be found in many stores.
Does Celsius come with a guarantee?
We were unable to find information on the official website about any guarantees. However, our readers have been going wild over the last few months taking advantage of the Special Trial Offer from Leptigen. Click above to learn more.
- 1. Effects of carnitine and taurine on fatty acid metabolism and lipid accumulation in the liver of cats during weight gain and weight loss. (2003). American Journal of Veterinary Research. November 9, 2016.
- 2. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. (2005). Obesity Research. November 19, 2016.
Celsius User Tips:
While we were researching these drinks we realized that Celsius drinkers have a lot of strong opinions to share about their experiences. Out of thousands of reviews and comments, we gathered some of the best tips to help you learn more about this product line.
“Simply drinking Celsius will not shed any pounds; it is meant to be a supplement to aid calorie burning.” Jessica
“I always purchase the Green Tea Peach Mango. I think it is the best flavor out of all.” Melanie
“It’s no magic bullet for weight loss, it must be combined with diet and exercise.” James
“I’m not crazy about the taste but this has way more vitamins and minerals than other energy drinks so I kept trying flavors until I found one I like.” Eric
“This has high levels of caffeine so make sure that you can tolerate that much before you drink it.” Katie
“It works pretty good as to the energy part but you need to watch how much you drink. It played havoc with my stomach.” Eddie
“The taste is pretty good and it really gives you a pick up, but you must be careful. It has an enormous amount of caffeine in it.” Debbie
Celsius Scientific Abstracts:
For pancreas, larynx, esophagus, and oral cavity cancer, the evidence for a shielding effect of vitamin C and accompanied components is significant and consistent. For stomach, breast, rectum, and cervix cancer, the evidence is just as strong. An array of lung cancer studies had discovered significant protective activities of vitamin C. It is possible that carotenoids, ascorbic acid, and other fruit traits work together. Raising intake of fruits and vegetables are encouraged. 
Nicotinic acid has been found to have favorable activities toward lipids and lipoproteins, giving it the ability to become an alternative to fibrates for treating mixed hyperlipidemia patients. Niacin may also be used either by itself or combined with other agents. Niacin has been employed in a plethora of various dyslipidemias. There needs to be a larger clinical trial with the inclusion of placebo to thoroughly verify its effects. 
Green tea catechins had significantly reduced body weight and had assisted in maintaining body weight following a period of weight-loss (microcirc=-1.31 kg; P<0.001). Suppression of this effect by participants with high habitual caffeine consumption (>300 mg per day) had not achieved significance (microcirc=-0.27 kg for high caffeine intake and microcirc=-1.60 kg for low regular caffeine consumption; P=0.09). A similar effect was noticed from catechins in Caucasian participants (microcirc=-0.82 kg) when compared to Asians (microcirc=-1.51 kg; P=0.37) but had not been significant enough. Epigallocatechin gallate-caffeine combination had a minor positive effect on weight-loss and weight management. In conclusion, the results had indicated habitual caffeine intake along with ethnicity could all be factors in influencing catechin effects. 
There has been a very well documented account of ginger and its anti-cancer properties due to its functional ingredients (gingerols, paradols, and shogal) which help prevent a variety of cancers. The study had concluded citing gingers favorable traits, but some ambiguities made the need for further research necessary.
It was found that individuals who consumed a high amount of caffeine experienced weight loss, fat mass reduction, and waist circumference decrease more so than those who intake moderate volumes of caffeine. There had been less of a reduction of resting energy expenditure along with the reduction of respiratory quotients during weight-loss (p < 0.01). In moderate caffeine intake individuals, during weight management, green tea had still decreased body weight, waist, body fat, and respiratory quotient, and resting energy expenditure had been raised in comparison to the restoration of the variables with placebo (p < 0.01). High caffeine intake users experienced no difference in weight management with intake of green tea. It had been concluded that high caffeine intake was associated with weight-loss via thermogenesis and fat oxidation. 
- 1. Vitamin C and cancer prevention: the epidemiologic evidence (1990). The American Journal of Clinical Nutrition. November 5, 2016.
- 2. New Perspectives on the Use of Niacin in the Treatment of Lipid Disorders (2004). JAMA Internal Medicine. November 5, 2016.
- 3. The effects of green tea on weight loss and weight maintenance: a meta-analysis (2009). International Journal of Obesity. November 5, 2016.
- 4. Anti-Oxidative and Anti-Inflammatory Effects of Ginger in Health and Physical Activity: Review of Current Evidence (2013). International Journal of Preventative Medicine. November 5, 2016.
- 5. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation (2005). Obesity Research. November 5, 2016.
Celsius Side Effects:
In a world of weight-loss supplements it’s easy to think the natural solution is the choice with the least amount of side effects. The truth is every formula is different. Each person reacts in their own way, so while Celsius side effects are relatively rare, that doesn’t mean they don’t happen for some users.
Anxiety is the feeling of nervousness, dread and feeling anxious. You may be restless, have issues with concentration, and in some cases, feel mild to severe jitters. On the physical side, you may feel shortness of breath, sweats, dizziness, or feel pain in the stomach.
What causes anxiety?
Anxiety is caused when there is a malfunction of brain circuits that control fear and other emotions. Anxiety can be a factor of a mental illness, although there are physical triggers as well, such as caffeine intake, stress, or certain medications. 
Lightheadedness is the unpleasant sensation of feeling faint, or in some cases, dizzy. Episodes of lightheadedness can be short-lived, or ongoing, which could be a cause of a more serious medical condition.
What causes lightheadedness?
Lightheadedness can be caused by a number of factors, all of which are most commonly related to the inner ears or nervous system. A temporary shortage of blood and oxygen to the brain may cause lightheadedness. In these cases, vomiting, diarrhea, or a drop in blood pressure can all contribute.
A headache is a dull, throbbing, or sharp pain in the head and neck. Headaches are typically categorized as migraines, tension headaches, or cluster headaches and although common, could be the result of a serious underlying medical condition if the symptoms persist.
What causes a headache?
Whenever the nerves or blood vessels around the brain become disrupted, a headache can occur. There are several factors which can trigger a headache, including stress, medications, or eating disorders. In addition, direct trauma to the head or increase in blood pressure could also be a factor.
Diarrhea is a condition in which three or more loose or watery stool occur in a day. Occasionally occurring in most people, although if symptoms persist this could lead to dehydration. Dehydration, in turn, can cause irritability and stress, which could make the diarrhea worse.
What causes diarrhea?
Diarrhea is most commonly caused by an infection in the intestines. This infection could be brought on by a virus, parasite, or bacteria. Diarrhea is typical with those who suffer from lactose intolerance. Consumption of artificial sweeteners is another trigger of this symptom. 
Celsius side effects are very uncommon, but there have been reports of diarrhea, headache, and lightheadedness, among others. In an effort to avoid an adverse reaction it’s always best to consult a physician before taking any supplement. This goes especially for those who are taking prescription medications, have a pre-existing medical condition of any kind, are under the age of 18, or are pregnant or nursing.
Celsius is a drink that is used to increase energy levels and promote weight-loss. Side effects are not common, though we pulled a few quotes from people who unfortunately experienced them.
“Once I drank Celsius, I immediately felt jittery” Maura
“Now when I take it, I get really light headed, unfocused, and riddled with anxiety…Also, wicked headaches.” Kyli
“About 20 minutes after my workout I started getting hot flashes, a sick stomach, and a little light headed.” Sondra
“Now I feel sick, I feel hot, sweaty, and I can barely breathe, I feel light headed even when I am sitting or lying down.” Paloma
“I got home and felt something in my stomach…Then I had very powerful bowel movement.” Betty
“I just drank the sparkling orange without working out and became very sick to my stomach, dizzy, and am experiencing the beginnings of a headache.” Holly
“These did absolutely nothing for me but make me sick I got dizzy and nauseous.” Michelle
“Very bad. Felt jittery 2 hours after [I] consumed it. Felt like I was out of breath and my heart was pumping like crazy.” Chaya
“Once I got a headache and once I got diarrhea, and once I just felt kind of sick.” Rickie
“This stuff is way too strong!! It gave me a headache and bloodshot eyes.” Kristen
Side effects are rare, so that’s why Leptigen has caught our attention. There’s no mention of adverse reactions and customer reviews are showing that dieters are seeing positive changes. Want to learn more? Click above.
Celsius is a "healthy energy drink" - according to the official website. There are a few stimulating ingredients in the mix, but the main formula is in a proprietary blend. This hides the amount of each ingredient. Celsius states at the bottom of their website that weight-loss will not happen without healthy lifestyle changes.
Celsius Ingredients and Supplement Facts
Serving Per Container: 4
|Amount per Serving||% DV|
|- Guarana Extract||*||*|
|- Green Tea Leaf Extract||*||*|
|- Ginger Extract||*||*|
Other Ingredients: Carbonated filtered water, citric acid, natural flavor, sucralose, beta-carotene
We reviewed Celsius ingredients in order to give you the facts you need.
Green tea is produced from the Camellia sinensis plant. It is prepared through steaming instead of fermentation, which is why is it considered healthier than black and oolong tea.
What Is It Supposed To Do?
Green tea is apparently useful for mental alertness, thinking, cancer, depression, liver disease, stomach issues, athlete’s foot, and much more.
Research done in Scotland has proved green tea can be quite beneficial for weight-loss. In their study, published in Clinical Nutrition, researchers noted that, “12 weeks of treatment with high-dose green tea extract resulted in significant weight loss, reduced waist circumference, and a consistent decrease in total cholesterol and LDL plasma levels without any side effects or adverse effects in women with central obesity.” 
Guarana Seed Extract
Guarana got its name from the infamous Guarani tribe, when they used certain seeds to brew a special drink. Now, the same guarana seeds are still used for medicines.
What Is It Supposed To Do?
Guarana seed extract is used as ailments for many health problems, including low blood pressure, fatigue, pain, heart stress, and more.
In 2006, a study was published in the European Journal of Medical Research regarding the effects of guarana. In their conclusion, the researchers stated, “A change in some outcome measures like: weight, BMI failed to produce significant difference between groups.”  Additionally, this was measured through the use of a supplement containing other herbal supplements.
Ginger is a plant originating in warmer areas of Asia, Africa, and South America. It is often used as a spice, as well as various medicines in the Middle East.
What Is It Supposed To Do?
Ginger is known to help reduce inflammation and nausea. It has also been marketed as a laxative.
A recent study was published in the European Journal of Nutrition evaluating the effects of ginger on weight loss. In the conclusion of the article, researchers stated that, “In conclusion, our findings demonstrate a minor beneficial effect of 2g ginger powder supplementation for 12 weeks on weight loss and some metabolic features of obesity.”
Chromium is an essential trace mineral founds in various foods and supplements. This should not be confused with hexavalent chromium, which is a known toxin.
What Is It Supposed To Do?
Chromium is thought to help normalize blood sugar levels by controlling the use of insulin in the body.
In an article from the University of Maryland Medical Center, there is discussion about the possible benefits of chromium in weight-loss, saying, “Studies have been mixed, with some finding that chromium may help people lose weight and build muscle, and others finding it has no effect.”
One that’s caught our eye is one called Leptigen. The clinically-tested ingredients have been shown to work and backed by positive customer feedback. Click above to learn more.
- 1. Therapeutic effect of high-dose green tea extract on weight reduction: A randomized, double-blind, placebo-controlled clinical trial (2016). Clinical Nutrition. October 30, 2016.
- 2. Efficacy Of 12 Weeks Supplementation Of A Botanical Extract Based Weight Loss Formula On Body Weight, Body Composition And Blood Chemistry In Healthy, Overweight Subjects – A Randomised Double-Blind Placebo-Controlled Clinical Trial (2006). European Journal of Medical Research. November 4, 2016.