Losing weight should be easy enough: Just eat the right amount of food containing the proper nutrients and exercise regularly. If only it were that simple. In the real world, hectic schedules and workplace candy dishes make dropping pounds a tall order. Although ditching the Doritos and keeping a regular date with the elliptical trainer can get you started, sometimes you need a little help shaving off extra inches.

Here’s where certain dietary supplements can step in. Studies suggest that supplemental fiber, 5-hydroxytryptophan (5-HTP) and hydroxycitric acid (HCA) have pound-dropping potential. Although some of the findings are preliminary, experts think these natural alternatives aid weight loss by increasing satiety, promoting fat burning, or elevating mood—unlike most “weight-loss” supplements on the market that rely on stimulants to jack up energy and distract you from eating.

Even when derived from natural sources, stimulants can cause anxiety, rapid heart rate, and digestive unrest, according to a 2004 Harvard Medical School meta-analysis of common weight-loss supplements published in American Family Physician. Plus, people often regain the weight once they stop taking stimulant-based supplements, says Jessica Crandall, RD, CDE, an American Dietetic Association spokeswoman. “Dieters rely too heavily on these products, instead of making the lifestyle, behavioral, and dietary changes necessary to sustain weight loss,” she says.

Here’s how supplementing with fiber, HCA, and 5-HTP may help you shed pounds without the side effects of stimulants.

Fiber
Abundant in a myriad of fruits, veggies, grains, and legumes, fiber absorbs water in the gut to make you feel full faster. It also delays digestion, which in turn keeps blood sugar stable, Crandall explains. The Institute of Medicine recommends 25 grams of fiber per day for women and 30 to 38 grams for men. But in reality, few people get that much from food alone. “Americans consume 10 to 12 grams per day, and that’s nowhere near enough,” Crandall says. Supplementing with fiber can get you up to the 25- to 35-gram range and possibly jump-start weight loss. The Harvard meta-analysis mentioned above showed that glucomannan, a plant-derived soluble fiber, promoted weight loss in three randomized controlled trials.

“Just don’t ramp up to 30 grams overnight, or you’ll get gassy and bloated,” Crandall says. Instead, she suggests adding 3 to 5 grams per day for one week, another 3 to 5 grams the next and so on, also increasing your water intake as you go.  Once you hit your fiber target, stay at that level, she says. “Anything more than 35 grams and you’re overdoing it.”

Hydroxycitric Acid

Hydroxycitric acid comes from the fruit of the Garcinia tree, which grows throughout India. It’s been on the weight-loss radar since 1970s studies showed large doses curbed hunger in rats. In a 2004 trial featured in Diabetes, Obesity and Metabolism, Georgetown University Medical Center researchers determined that supplemental HCA can trigger weight loss in obese adults without affecting the body’s central nervous system, as stimulants do. “HCA has two major known mechanisms of action,” says Harry Preuss, MD, the study’s lead author. “The first is appetite suppression and the second is a metabolic block that decreases the production of fats from carbohydrates.”

To tap into HCA’s weight-loss potential, “divide 2,800 mg into three daily doses taken 30 to 60 minutes before meals,” Preuss says. HCA comes as a stand-alone supplement, but it’s more frequently found in combination formulas. “I like a product that also includes calcium, vitamin K, and magnesium,” Preuss says.

5-Hydroxytryptophan

Used predominantly to boost mood, 5-hydroxytryptophan increases the feel-good neurotransmitter serotonin and may help with weight loss.  “Supplemental 5-HTP can help you lose weight by improving appetite control and reducing food cravings,” says Sherry Torkos, a pharmacist and author of The Canadian Encyclopedia of Natural Medicine (Wiley, 2008) and Saving Women’s Hearts (Wiley, 2011). “The thought is that craving carbohydrates, binge eating, and stress-induced eating are associated with low serotonin levels. By boosting serotonin, 5-HTP may help with weight management.”

Torkos recommends taking 100 mg 20 minutes before each meal, up to three times a day. “If you don’t achieve desired results after four weeks, increase to 200 mg three times a day,” she says. “Doses of 300 mg have also been well tolerated, but don’t exceed a total of 900 mg per day.”

Still, as with any supplement, 5-HTP is not a golden ticket to getting—and staying—slim. “Use 5-HTP to complement an overall approach that includes healthy eating and exercise,” Torkos says. “The supplement can help you reach your weight-loss goals, but you must have these lifestyle approaches in place to maintain results.”