10 Natural Appetite Suppressants

A natural appetite suppressant is a supplement or food that helps curb hunger or increase the rate of metabolism.

Many supplements marketed for weight loss have been found to be contaminated with dangerous substances. In general, their use is not advisable.

This article discusses some available natural appetite suppressants, their studied dosages, and their safety.

Sustainable Weight Management

It is vital to note that a sustainable approach to weight management and overall health involves the following:

• Getting regular exercise that you enjoy 
• Managing stress
• Following a balanced diet
• Getting social support and mental health support where needed

A balanced diet rich in the following can help your overall health:

• Lean protein
• Fiber
• Healthy fats
• Fruit and vegetables
• Adequate hydration, especially from drinking water

Read on for more information about the uses and safety of appetite-suppressant supplements and foods.

What Appetite Suppressant Supplements Are Available?

Some supplements, nutrients, and foods have been studied for managing appetite or changing body composition.

Fiber

Fiber is a type of complex carbohydrate found commonly in plant-based foods. The human body cannot fully digest or absorb. It's a vital part of a healthy diet and comes in two primary forms:

• Soluble fiber: Gel-like, reduces cholesterol and blood sugar
• Insoluble fiber: Bulk-forming, promotes regular bowel movements

Overall, fiber appears to decrease appetite by increasing satiety. Some evidence suggests that psyllium, glucomannan, and agar have the following properties:

• Decreases cholesterol levels
• Decreases blood sugar levels
• Decreases absorption of carbohydrates
• Delays gastric emptying 
• Promotes a feeling of fullness

Interactions: Fiber can decrease the absorption of certain medications, thereby decreasing how well they work. Take your medications at least two to three hours apart from fiber supplements.

The following includes information on a few different fiber supplements.

Psyllium

Psyllium is a soluble fiber that forms a gel-like substance in the stomach, which creates a sensation of fullness and thereby decreases appetite.

Dosage: The daily dose of psyllium is 3 to 10.5 grams (g) by mouth.

Side effects: Common side effects of psyllium include stomach discomfort and bloating.

Precautions: Do not take psyllium if you have appendicitis or intestinal blockage.

Interactions: Avoid taking the following medications within three hours of taking psyllium.

• Thyroid medications, like Synthroid (levothyroxine)
• Lanoxin (digoxin)
• Aspirin
• Macrobid (nitrofurantoin)

Glucomannan

Glucomannan is a soluble fiber found in roots, tubers, and many plant bulbs.  

Dosage: The daily dose of glucomannan is 2–3 g by mouth.

Side effects: No side effects were noted in the studies.

Agar

Agar has been shown to reduce body weight and fat in a 16-week study of 76 people with type 2 diabetes.

Dosage: The daily dose of agar is 180 g by mouth.

Side effects: No side effects were noted in the clinical studies.

Lean Protein

Getting enough protein from your diet is essential to help build and maintain muscle mass.

Uses: Protein consumption, such as whey protein, has had the following effects.

• Increased satiety hormones, in turn, helped to regulate appetite  
• Reduced body weight and fat 

Dosage: The International Society of Sports Nutrition recommends that exercising individuals consume at least 1.4 to 2.0 g of protein per kilogram (kg) of body weight (g/kg) daily. Average adults need around 0.8 to 1.0 g/kg.

Precautions: Caution should be taken if you have kidney or liver problems. Consult your healthcare provider or registered dietitian to determine the appropriate protein intake if you have kidney or liver problems.

Interactions: Protein can interfere with the absorption of levodopa (a medication used for Parkinson’s disease).

Calcium and Vitamin D

Calcium and vitamin D are essential for the following:

• Building and maintaining healthy bones
• Maintaining cardiovascular health
• Regulating hormones
• Regulating your immune system

Getting calcium from foods is generally better than getting it from supplements. Good food sources of calcium include the following:

• Dairy products (yogurt, kefir, milk)
• Dark, leafy greens

Uses: One study examined the effect of 600 milligrams (mg) of elemental calcium and vitamin D, using 125 international units (IU) of vitamin D3, on people with the following characteristics.

• Aged 18 to 25 years
• Being overweight or having obesity
• Had a daily calcium intake below 600 mg

Calcium and vitamin D supplementation for 12 weeks helped with fat loss. Moreover, researchers suggested that vitamin D deficiency increased appetite.

Calcium

Dosage: The recommended daily amounts of calcium are as follows.

• 19–50 years (males and females): 1,000 mg
• 51–70 years (males): 1,000 mg
• 51–70 years (females): 1,200 mg
• Older than 70 years (males and females): 1,200 mg

Interactions: Calcium can interfere with the absorption of certain antibiotics, such as the following.

• Vibramycin (doxycycline)
• Cipro (ciprofloxacin)
• Levofloxacin

Medications used for an underactive thyroid, such as Synthroid (levothyroxine), also interact with calcium.

Consult your pharmacist about the appropriate timing of taking your medications and supplements.

Vitamin D

Vitamin D is best absorbed when taken with a healthy fat.

Dosage: The recommended daily amounts of vitamin D are as follows.

• 19–50 years (males and females): 600 international units (IU)
• 51–70 years (males and females): 600 IU
• Older than 70 years (males and females): 800 IU

Interactions: Certain medications, such as Alli (orlistat), can block the absorption of fat-soluble vitamins like vitamin D.

Getting enough vitamin D is important, particularly during darker months or at higher latitudes.

Probiotics and Synbiotics

Probiotics are the beneficial gut bacteria or yeast. Prebiotics are nondigestible fibers that support the growth of those microorganisms. Synbiotics refer to the combination of both probiotics and prebiotics.

Uses: Supplementation with synbiotics for three months increased the abundance of beneficial gut bacteria in people who are overweight or obese.

Inulin, a type of fiber extracted from chicory, is a prebiotic that had the following effects in people with type 2 diabetes:

• Reduced weight
• Increased satiety
• Improved blood sugar levels

However, the effects of inulin on weight and satiety in people who are overweight or have obesity but do not have diabetes are unclear.  

Dosage: The following dosages have been used in clinical studies.

• Probiotic dose: One capsule containing 69 mg or 15 x 10⁹ colony-forming units (CFU) of Lactobacillus acidophilus, Bifidobacterium lactis, B. longum, and B. bifidum by mouth
• Prebiotic dose: 5.5 g per day (2.75 g of galactooligosaccharides and the remaining simple sugars) by mouth
• Inulin dose: 10 g per day by mouth

Side effects: Some side effects of probiotics and prebiotics include the following.

• Abdominal cramping
• Diarrhea
• Soft stools
• Constipation
• Bloating
• Flatulence

Precautions: Some probiotics have caused infections in people with a compromised immune system. Before taking probiotics, talk with your healthcare provider if you have a weakened immune system.

Probiotics and prebiotics are safe during and after pregnancy and lactation.

Interactions: Antibiotics can decrease the effects of probiotics. As such, take probiotics at least two hours before or after antibiotics.

Green Tea Extract

Green tea contains the catechin (potent antioxidant) epigallocatechin-3-gallate (EGCG) and caffeine.

Uses: Green tea has been shown to have the following effects.

• Increased fullness
• Decreased appetite
• Blocked enzymes responsible for breaking down fat and carbohydrates
• Driven gut bacteria to produce short-chain fatty acids, positively affecting gut health

The caffeine in green tea has been proposed to contribute to the following:

• Appetite suppression
• Increased metabolism

Dosage: Green tea extract doses range from 100 to 460 mg per day by mouth.

As green tea contains caffeine, it is advised that you limit your caffeine intake to no more than about 300 mg if you are pregnant or breastfeeding.  

Side effects: No side effects were reported in the studies.

Precautions: Green tea may increase the risk of congenital disabilities caused by folic acid deficiency.

Tea can also decrease iron absorption. You may want to avoid drinking it with your meals.

Liver problems have been reported with using green tea extract in pill form. If you have liver disease, consult a healthcare provider before taking products with green tea extract.

Interactions: Green tea and EGCG have decreased intestinal absorption—and thus, the therapeutic effects of—some of the following drugs.

• Corgard (nadolol), a beta-blocker
• Lipitor (atorvastatin), a cholesterol-lowering drug
• Prinivil (lisinopril), a blood-pressure-lowering drug
• Jantoven (warfarin), a blood-thinning drug
• Seroquel (quetiapine), an antipsychotic
• Clozaril (clozapine), an antipsychotic
• Sutent (sunitinib), an anticancer drug

Animal studies indicate that green tea extract and EGCG increase the extent of absorption of the following drugs:

• Cardizem (diltiazem)
• Verelan (verapamil)
• Nolvadex (tamoxifen)
• Zocor (simvastatin)
• Efudex (5-fluorouracil)
• Cardene (nicardipine)

However, human studies are needed to confirm these results.

Alpha Lipoic Acid (ALA)

ALA is an antioxidant fatty acid that helps the body make energy from sugars.

Uses: Preliminary evidence suggests ALA had the following effects.

• Suppressed appetite
• Increased the breakdown of fat
• Reduced fat generation
• Improved blood sugar metabolism in people with type 2 diabetes

Dosage: The dose of ALA ranges from 300 to 2,400 mg per day by mouth.

Side effects: Some of the side effects of ALA are as follows.

• Abdominal pain
• Nausea
• Urticaria (hives)
• Itching
• Hypoglycemia (low blood sugar)

Precautions should be taken in the following instances.

• Pregnancy: ALA has been used safely in pregnancy in doses of up to 600 mg daily for up to four weeks. However, the safety of ALA use during breastfeeding is unknown.
• Children: Seizures, vomiting, and unconsciousness have been reported in children aged 14 months to 16 years who took 2,400 mg of ALA as a single dose. 
• Surgery: Because ALA might interfere with blood sugar control during and after surgery, ALA should be stopped two weeks before elective surgical procedures.
• Vitamin B1 deficiency: ALA can lower your body's vitamin B1 (thiamine). Excessive alcohol intake can worsen vitamin B1 deficiency.

Interactions: ALA may interact with the following medications.

• Anticancer drugs: ALA is an antioxidant and thus might decrease the effects of drugs used for cancer. Always ask your oncologist before starting any dietary and herbal supplements, including ALA. 
• Blood thinners: Taking ALA with blood thinners, such as Eliquis (apixaban), Xarelto (rivaroxaban), and Jantoven, might increase the risk of bruising and bleeding.
• Thyroid hormone drugs: ALA appears to decrease the effects of thyroid hormone drugs, such as Synthroid.
• Antidiabetic drugs: Since ALA might cause blood sugar to drop too low, be sure to ask your healthcare provider before starting ALA and watch your blood sugar closely.

Conjugated Linoleic Acid (CLA)

Conjugated linoleic acid (CLA) is a polyunsaturated fatty acid found in the following foods:

• Dairy products
• Beef
• Lamb

Uses: A review suggested CLA had the following effects.

• Decreased the size of fat cells
• Blocked fat production
• Changed the gut microbiota

While the effect of CLA on appetite is unclear, a review of a group of studies indicated that taking 3.4 g of CLA daily for 12 weeks in people over 44 years of age promoted weight and fat loss. Overall, early evidence suggests that CLA could be used for treating obesity in addition to dietary modification. However, further research in humans is needed to confirm the results.

Dosage: The dose used in clinical trials ranges from 1.5 to 6.8 g per day by mouth.

Side effects: Most reported side effects were gastrointestinal side effects.

• Abdominal discomfort
• Bloating
• Loose stools
• Indigestion

Precautions: Caution should be taken in people with the following conditions or characteristics.

• Diabetes: Some animal and human studies have shown that CLA supplementation can increase inflammation and insulin resistance (when muscle, fat, and liver cells don’t respond well to insulin and can’t take up glucose from the blood, requiring more insulin). Consult with your healthcare provider before starting ALA if you have diabetes.
• Pregnant or breastfeeding: The safety of CLA in pregnancy or breastfeeding is unknown. 
• Children: While research on the safety of CLA in children is lacking, one clinical trial looked at the effect of using CLA in children with asthma aged between six and 18 years. No adverse effects were noted in the study.
• Liver disease: Animal studies showed that CLA supplementation resulted in an enlarged liver and fatty liver. However, a 12-week study conducted in females who were overweight or had obesity found that CLA was well tolerated and safe for the liver with no significant changes in liver function tests. However, the study was limited in its study population. Further research, including more diverse populations, is warranted. 

Interactions: Until more research is done on the drug interactions with CLA, it is unclear how CLA interacts with prescription and nonprescription medications.

Tyrosine

Uses: Besides other amino acids in whey protein, tyrosine has had the following effects.

• Decreased hunger
• Increased satiety
• Increased the glucagon-like peptide 1 (GLP-1), a hormone that increases satiety, among other functions

However, outcomes from the study above are limited because it was conducted in only eight females with obesity. Further studies with a larger sample size and a more diverse population are needed.

Dosage: The specific amount of tyrosine was not explicitly stated in the study, but the dose of the whey protein powder was 45 g dissolved in 300 milliliters (mL) of semi-skim milk. More specifically, 100 mL of the drink was given by mouth three times every five minutes. 

Interactions: Caution should be taken if you take the following medications.

• Levodopa: Tyrosine and protein, in general, compete with levodopa for gut absorption and thus lower the efficacy of levodopa.
• Thyroid drugs: Tyrosine is one of the components used to produce thyroid hormone. Taking tyrosine with a thyroid replacement drug may increase thyroid hormone levels. Therefore, avoid tyrosine if you have thyroiditis, hyperthyroidism, or Graves’ disease.
• Monoamine oxidase inhibitors (MAOIs): Tyrosine is broken down into tyramine. High levels of tyramine can cause high blood pressure and migraines. Drugs such as MAOIs prevent the breakdown of tyramine and, therefore, cause a build-up of tyramine. Talk to your healthcare provider before starting tyrosine if you take MAOIs or have high blood pressure or migraines.
  

Bitter Orange (Citrus Aurantium)

Uses: Bitter orange (Citrus aurantium) contains a chemical compound called p-synephrine, which is known to have the following effects.

• Suppress appetite (via slowed movement of food through the gastrointestinal tract)
• Increase energy expenditure and fat breakdown

Despite its popular use as an over-the-counter weight loss product, the quality of evidence is low to support the use of bitter orange for appetite control and weight loss in humans.

Dosage: The commonly used doses of p-synephrine range from 25 to 100 mg per day by mouth.

Precautions: Some studies have shown that bitter orange increased blood pressure and heart rate with long-term use (i.e., eight weeks), although conflicting evidence exists. Caution should be taken if you have high blood pressure, irregular heart rate, or other cardiovascular diseases. 

The safety of bitter orange is unknown in the context of pregnancy or breastfeeding.

Interactions: Bitter orange contains furanocoumarins, compounds that block the activity of the drug-metabolizing enzyme cytochrome P450 (CYP) 3A4.

Some studies show that bitter orange juice increases blood levels of drugs, such as Neoral (cyclosporine) and Invirase (saquinavir), broken down by the CYP3A4 liver enzyme.

DHEA

DHEA is a hormone produced by the adrenal glands and the liver. It serves as a precursor to sex hormones.

Uses: One clinical study suggested DHEA favorably impacted body composition.

Dosage: One study used 100 mg per day of DHEA. Dosages may range between 25 mg and 100 mg per day. Using DHEA at high doses (i.e., doses higher than 50 to 100 mg per day) or for an extended period can increase the risk of severe side effects.

Precautions: Caution should be taken in the following situations.

• Pregnancy and breastfeeding: DHEA can increase androgen levels and harm the baby. Do not use DHEA if you are pregnant or breastfeeding. 
• Diabetes: DHEA can affect how insulin works in the body. Monitor blood sugar levels closely if you have diabetes and are taking DHEA.
• Hormone-sensitive conditions such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: Since DHEA can be converted to estrogen, you should avoid DHEA if you have conditions that are made worse by estrogen. 
• High cholesterol: DHEA might decrease high-density lipoprotein cholesterol ("good" cholesterol). Talk with your healthcare provider before starting DHEA if you have high cholesterol or heart disease.
• Liver problems: As DHEA can worsen liver problems, avoid DHEA if you have liver problems.
• Depression and mood disorders: Due to the risk of excitability, impulsiveness, and irritability, talk to your healthcare provider if you have mood disorders. 
• Polycystic ovary syndrome (PCOS): Avoid DHEA if you have PCOS because DHEA might worsen PCOS.

Interactions: DHEA may interact with some of the following medications.

• Faslodex (fulvestrant): Fulvestrant is a drug that blocks the action of estrogen. DHEA might increase estrogen in the body and decrease fulvestrant's efficacy. Do not take DHEA if you are taking fulvestrant. 
• Aromatase inhibitors: Aromatase inhibitors, such as Arimidex or anastrozole, work to lower estrogen levels in the body by blocking the enzyme that converts androgen to estrogen. DHEA might decrease the effects of aromatase inhibitors.
• Nolvadex (tamoxifen): Tamoxifen is a drug used to treat breast cancer and prevent breast cancer recurrence. It is a selective estrogen receptor modulator, meaning it has an antiestrogenic and estrogen-like effect depending on the tissues it acts on. DHEA increases estrogen levels and thus decreases the effects of tamoxifen. 
• Estrogen: Taking estrogen with DHEA might cause you to have too much estrogen in the body.
• Testosterone: Because DHEA can be converted to testosterone, taking DHEA with testosterone can cause you to have too much testosterone in the body. 
• Blood-thinning drugs: DHEA might increase the risk of bruising and bleeding if taken with drugs that slow blood clotting. 
• Medications metabolized by the CYP3A4 liver enzyme: DHEA may increase or decrease the effects and side effects of drugs metabolized by CYP3A4.
• Antidepressant drugs: Taking DHEA with antidepressant drugs might increase the risk of severe side effects. 
• Halcion (triazolam): Triazolam is a drug that is used short term to treat insomnia (difficulty sleeping). DHEA might increase triazolam levels and, therefore, its side effects.
• Tuberculosis vaccine: DHEA might decrease the effects of the tuberculosis vaccine and, therefore, should be avoided if you are receiving a tuberculosis vaccine. 

Some supplements that interact with DHEA include, but aren't limited to, the following:

• Garlic (increases bleeding risk)
• Ginger (increases bleeding risk)
• Ginkgo (increases bleeding risk)
• Panax ginseng (increases bleeding risk)
• Licorice (increases levels of DHEA)

Summary

There are no miracle dietary supplements that help with weight loss.

Furthermore, weight loss supplements have been found to be contaminated with dangerous substances. Their use is generally not advised.

A sustainable approach to weight management best involves a balanced diet and getting regular exercise that you enjoy.