Caffeine + Synephrine - GymBeam

Caffeine + Synephrine by GymBeam is a two-ingredient food supplement in capsule form. One capsule contains 200 mg of caffeine and 20 mg of synephrine derived from bitter orange extract (Citrus aurantium) at a ratio of 100:1, standardized to 96% synephrine.

What do these numbers mean in practice? The 100:1 ratio means that one hundred grams of dried raw material were used to produce one gram of extract. Standardization to 96% means that synephrine itself accounts for 96 percent of the extract’s weight. To obtain 20 mg of synephrine, you therefore need approximately 20.8 mg of extract – and those 20.8 mg of extract represent 2.08 grams of dried bitter orange peel.

These are verifiable figures, not marketing claims. You can calculate them yourself using the information on the label, and that is precisely the difference compared with products that list only “bitter orange extract” without specifying a ratio or standardization.

Pre-workout supplements are most commonly sold as powder in a tub with a scoop. That sounds more convenient than it actually is.

A scoop is not precise. The powder settles during transport, it packs differently at the beginning and end of the tub, and the difference between a level scoop and a heaped one can be tens of percent. When the difference between 150 and 250 mg of an ingredient is noticeable, that matters. A capsule is measured during manufacturing. Take one and you get exactly 200 mg of caffeine and 20 mg of synephrine. The same amount every time. No weighing, no scoop, no guesswork.

Then there is portability. Ninety capsules fit in a pocket of your gym bag. You are unlikely to take a tub of powder and a scoop on a business trip or holiday. And one more thing: a capsule has no taste. You do not have to worry about whether you like the flavour, whether the powder dissolves well, or whether it leaves sediment at the bottom of your shaker.

Caffeine is an alkaloid that occurs naturally in more than sixty plants, including coffee plants, tea plants, cacao and guarana. It is the most extensively studied active substance in the human diet.

The extent of the research can be summed up in one number. A review in the British Journal of Sports Medicine examined not individual studies, but meta-analyses themselves, and found twenty-one.⁵ Most ingredients in dietary supplements do not have even one. According to this review, caffeine was ergogenic—that is, it enhanced performance—in endurance, strength, muscular endurance, power, jumping and movement speed.

One finding runs counter to a widespread belief. It is commonly thought that caffeine taken before training no longer works for people who drink coffee every day. A meta-analysis in Sports Medicine examined this and did not confirm it: habitual coffee consumption does not eliminate the ergogenic effect.⁶ People do, however, respond to caffeine differently, and it is not a matter of psychology: variants of the CYP1A2 gene, which encodes the enzyme responsible for most caffeine metabolism, play a decisive role.⁷ That is why one person can sleep after two coffees, while another cannot fall asleep after a single afternoon coffee.

This leads to the most practical rule. The elimination half-life of caffeine is approximately five hours.¹ If you take a capsule at four in the afternoon, you will still have roughly 76 mg in your body at eleven at night—about as much as in a cup of coffee. Therefore, take it in the morning or before training, never in the afternoon.

Safety guidance. EFSA states that single doses of up to 200 mg do not raise safety concerns for healthy adults, even when taken two hours before intense physical activity; it gives 400 mg as a reference value for daily intake.¹ The capsule is at the upper limit for a single dose and half the daily reference value.

Synephrine is an alkaloid found in citrus peel. The richest source is bitter orange, the same fruit used to make English marmalade. Supplements use the p-synephrine form, which is also the form that occurs naturally in citrus fruit.

Research on this substance has been conducted primarily by one Spanish group, whose studies share a common methodology: double-blind crossover designs with measurements of respiratory gas exchange. The first finding, from 2016, showed that p-synephrine increased the maximum rate of fat oxidation by 0.11 g/min. The authors calculated that this amounted to approximately seven additional grams of fat per hour of exercise, at the same intensity and the same heart rate.⁸ That last point matters more than the number itself: the participants did not exercise harder; their bodies simply used a different fuel.

A dose-dependent study from 2018 added to these findings. Seventeen volunteers completed four trials with a placebo or 1, 2 and 3 mg per kilogram. Maximum fat oxidation rose from 0.35 to 0.55 g/min at doses of 2 and 3 mg/kg. None of the doses affected heart rate or energy expenditure.⁹

However, the same group also published a study in 2022 involving healthy, active women, and found no effect.¹⁰ That belongs in the overall picture just as much as the positive findings.

One point should be stated plainly. Those studies used 2 to 3 mg per kilogram, which amounts to 140 to 210 mg for a person weighing 70 kilograms. A capsule contains 20 mg. The 1 mg/kg dose, equivalent to 70 mg, did not reach statistical significance.⁹ This is not a formulation error: France permits a maximum of 20 mg of synephrine in a supplement, and other markets have similar limits. The doses studied could not be marketed in the EU.

The laboratory did not detect any of the heavy metals tested at levels above the limit of quantification.² These are not values just below the limit; they are values the instrument could not detect. The sample complies with Regulation (EU) 2023/915³ on maximum levels for contaminants in food.

The microbiological panel is also broader than standard testing: in addition to Salmonella, it tests for yeasts, moulds and coliform bacteria—three parameters monitored in plant extracts precisely because the raw material is dried plant matter.