Guide
Thermogenic Fat Burner Side Effects and Evidence, Explained Plainly
Thermogenic fat burner side effects mostly come from caffeine and plant extracts: jitters, poor sleep, stomach upset and a faster heartbeat. Rare liver injury is linked to green tea extract. In trials, cayenne heat compounds raised energy use by about 50 kcal a day. FDA says most healthy adults can have 400 mg of caffeine a day.
- 50 kcalextra energy a day in capsaicinoid trials
- 400 mgcaffeine a day, FDA adult guide
- 2 namesin the blend with caffeine
- 0 mgcaffeine printed on the label
Written by the SodaBurn label deskUpdated
The word
What are thermogenic supplements?
Thermogenic supplements are products sold to raise the body's heat output, which is the energy it uses. Makers pair the word with "fat burner", but the word describes a sales idea, not a proven effect. The NIH says little is known about whether weight loss supplements work (NIH ODS, Weight loss supplements).
Your body already makes heat when it digests food, moves and keeps you warm. Researchers measure this as energy expenditure, counted in kilocalories (kcal), the "calories" on a food label.
The front of the SodaBurn label says "Metabolic & Thermogenic Support†". The dagger leads to the FDA statement that the claim has not been evaluated.
What trials found
Do thermogenic fat burners work?
Thermogenic fat burners work only a little in the best trials. Capsaicinoids, the heat compounds in chili, raised energy use by about 50 kcal a day across 20 trials, and the authors call them no magic bullet (Whiting 2012, Capsaicinoids review).
Coleus forskohlii is another plant sold for this. A 2026 review of four trials saw a possible fat mass effect but inconsistent weight results (2026 review, Coleus forskohlii). The authors ask for longer, better trials.
| Name | Sold as | What trials found | On the SodaBurn label |
|---|---|---|---|
| Cayenne (capsaicinoids) | Heat maker | About 50 kcal a day more energy used | Cayenne fruit extract, at most 1.55 mg |
| Coleus forskohlii | Fat mass aid | Possible fat mass effect, mixed weight results | At most 1.72 mg |
| Guarana | Energy and appetite | Weak, short evidence | At most 3.87 mg |
| Green tea | Catechins and caffeine | See the next question | At most 2.21 mg |
"At most" is arithmetic from the blend order, not a measured amount. The label prints no amount for any single name.
Green tea
Is green tea thermogenic?
Green tea is called thermogenic because its catechins and caffeine may nudge energy use, but the weight evidence is mixed. A Cochrane review of six studies outside Japan found a mean difference of about 0.04 kg against control (Cochrane, Green tea for weight loss (2012)).
A 2009 meta-analysis of 11 studies found a small positive effect, about 1.31 kg, for catechins or a catechin and caffeine mix (Hursel 2009, Green tea meta-analysis). The two reviews used different studies and reached different answers. Read both as small and uncertain.
None of those studies used the green tea leaf extract in SodaBurn. Its ceiling is 2.21 mg per 1 ml. Details are on the green tea extract page.
Side effects
What are the side effects of thermogenic fat burners?
The side effects of thermogenic fat burners are mostly those of caffeine. FDA lists a rapid heartbeat, palpitations, high blood pressure, insomnia, anxiety, jitters, upset stomach, nausea and headache (FDA, How much caffeine is too much).
Guarana seeds contain caffeine. Memorial Sloan Kettering lists nausea and insomnia as common, and says high doses may cause heart rhythm changes and high blood pressure (MSK, Guarana). Green tea also contains caffeine, so two names in the blend can add up.
FDA says most healthy adults can have about 400 mg of caffeine a day without negative effects. The label does not print the caffeine in SodaBurn. The bars below set each ceiling next to amounts a study or an authority used.
SodaBurn: 2, 3 or 6 bottles1 fl oz (30 ml) a bottle · 1 dropperful a day · 60-day money-back guarantee
See packsRare but serious
Can green tea extract harm the liver?
Green tea extract can harm the liver in rare cases. NCCIH says liver injury is uncommon but reported, mainly with extract in tablets or capsules (NCCIH, Green tea). A USP expert panel linked it to extracts rich in EGCG, taken in large bolus doses on an empty stomach (USP, Green tea extract liver review).
Brewed tea was not the problem in that research. Concentrated extracts were. We cannot say how this applies to the tiny ceiling of green tea in a blend, and no source tells us.
Yellow skin or eyes, dark urine or pain under the right ribs. Chest pain, trouble breathing, fainting or a racing heartbeat that will not settle: call 911.
Who should ask first
Who should ask a doctor before using a thermogenic supplement?
Anyone on medicine or with a health condition should ask a doctor or pharmacist before using a thermogenic supplement. Keep taking prescribed medicine, and never stop or change it because of a supplement.
- You take diabetes medicine or insulin, blood thinners, or blood pressure or heart medicine.
- You take stimulants, ADHD medicine or seizure medicine.
- You have liver or kidney disease, or surgery soon.
- You are pregnant or nursing, or under 18.
Weight care rests on food, activity, sleep and stress care at about 1 to 2 pounds a week (CDC, Steps for losing weight). See the side effects page and the safe weight loss basics.
FAQ
SodaBurn questions people ask
What does thermogenic mean on a supplement label?
Thermogenic means heat-producing. On a label it hints that a product raises the energy your body uses. It is a sales word, not a measured result, and the dagger statement says FDA has not evaluated the claim (FDA, Q&A on Dietary Supplements).
Is a thermogenic the same as a fat burner?
Sellers use the two words together, but a thermogenic is just one kind of claim. No source we read shows that any fat burner removes fat. The best trial gap we found was about 50 kcal a day for chili compounds.
Do thermogenics make you jittery?
They can, mainly when they hold caffeine. FDA lists jitters, anxiety, insomnia and a rapid heartbeat as caffeine warning signs (FDA, How much caffeine is too much). Guarana and green tea both contain caffeine, and the SodaBurn label prints no amount.
Can thermogenic supplements raise blood pressure?
Caffeine and guarana can. FDA lists high blood pressure among caffeine's warning signs (FDA, How much caffeine is too much). If you have blood pressure or heart problems, ask your doctor first.
How much caffeine is too much with a thermogenic?
About 400 mg a day is not generally linked to negative effects in most healthy adults (FDA, How much caffeine is too much). Count coffee, tea, soda and energy drinks too. Your own limit may be lower.
Is green tea extract safer than other thermogenics?
Not by default. Liver injury is uncommon but reported with green tea extract (NCCIH, Green tea). Natural does not mean safe.
Who wrote this
Written and reviewed by
Pages built from the label, the brand panels and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is the information site for a USA Authorized SodaBurn Retailer. It is not the manufacturer or a distributor named on the label. We earn money when you buy through our order links.
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