What Happened to Synephrine?
Synephrine started dissappearing from supplement formulas in 2016, and now in 2017 and 2018 it’s tough to find synephrine anywhere. For example, Cellucor’s C4 ingredients were updated to remove synephrine in 2016. So what happened to this ingredient?
In early 2016, the FDA issued warning letters to companies with methylsynephrine in their supplements. Since this is very similar to synephrine, aside from the methyl group, companies were prudent to remove this ingredient from their formulas.
But despite many companies removing synephrine from their formulas, some brands decided to keep the ingredient. You can still find synephrine from Primaforce’s Syneburn and in Legion Athletics’ Phoenix fat burning supplement. If you prefer bulk powder, you can still get synephrine from Liftmode.
What is Synephrine HCL?
Synephrine HCL is a naturally occurring alkaloid chemical compound found plants and extracted for use as a supplement. Bitter orange is the most popular synephrine plant and has a history of its own.
The use of bitter orange in the Americas dates back to the 1500’s, but has roots in China and groups indigenous to the Amazon jungle. These Chinese used bitter orange, usually in a tonic, to help with gastrointestinal issues like nausea, indigestion and constipation, while it was traditionally used in Brazil as anticonvulsant and to help with anxiety and sleeplessness. The vast differences in how these two cultures on different sides of the planet make it easy to understand why some see bitter orange as a magical supplement.
Bitter orange is currently used for a number similar issues as well as some more modern-day troubles like weight loss and as an aid in the battle against athlete’s foot. Synephrine is one of the main compounds in bitter orange and thought to be the foundation of the plant’s healing qualities.
Synephrine’s molecular structure is similar to ephedrine, arguably the most effective fat burning ingredients. Ephedrine can no longer be sold as a dietary supplement (and neither can methylsynephrine), which is why synephrine is the next best substitute. Synephrine’s metabolite is octopamine, which is another supplement promoted for its fat burning potential.
Synephrine HCL Uses
While bitter orange has a vast scope of potential uses, synephrine has been primarily used and studied for its effects on weight and fat loss. It does have some other interesting uses as well and, if differences in bitter orange use are any indicator, the uses will continue to span multiple areas over time.
- Weight Loss. Synephrine is often compared to ephedrine, the banned stimulant that was once the basis of many weight loss supplements. In fact, when ephedrine was banned, many supplement manufacturers replaced ephidrine with synephrine. Clinical studies have backed up synephrine’s positive impact on fat burning and weight loss. Synephrine helps increase the body’s metabolic rate and increases lypolysis (fat breakdown). It also functions as an alpha-androgenic antagonist. Synephrine works with receptors located in fat tissue that help enhance the lypolysis within that tissue and with receptors that increase thermogenesis of muscle, which also results in weight loss. [2, 3]
- Appetite Supressant. Synephrine’s stimulant properties make it an effective appetite suppressant. Reducing caloric intake is the key to rapid fat loss. Using an appetite supressant can help you curb cravings and make it easier to eat healthy. 
- Muscle uptake of glucose. Synephrine can stimulate glucose uptake by skeletal muscle. This function has potential in a couple areas. First, it helps you lose fat by removing excess glucose from the bloodstream and second, it provides muscles with glucose that can be used efficiently for energy. More intramuscular glucose could lead to greater muscle volume and strength.
Synephrine HCL Supplement Side Effects
When supplementing with synephrine HCL you may experience headaches. Synephrine is a stimulant, so it is important to start at a low dosage to assess tolerance.
Most synephrine-containing products on the market recommend up to 100mg/day for weight loss benefits, even though researchers believe doses as small as 35mg could be effective. Synephrine HCL does have synergism with caffeine, so if you’re particularly sensitive to caffeine, it’s best to start very small with synephrine if mixing with caffeine. To avoid toxicity, dosages should not approach or go over the 200mg/daily mark. 
Start with 10 to 20mg to assess your tolerance. Then, if you do not experience negative side effects, take another 20mg after at least 2 hours. Do not exceed a dosage frequency of once every 2 to 4 hours and do not take within 4 hours of bedtime. Synephrine’s half-life is around 2 hours.