Dietary Supplements

What are dietary supplements?

Dietary supplements are meant to supplement your diet. They can come as pills, powders, shakes, bars, and more. It is important to remember that dietary supplements do not go through the same testing that drugs do. This is an index of herbs and dietary supplements and their effectiveness, usual dosage, and drug interactions.

What is in dietary supplements?

Dietary supplements may contain herbs, vitamins, minerals, amino acids, and enzymes. It is important to note that "supplements are not intended to treat, diagnose, prevent, or cure diseases" ( FDA), and therefore the ingredients cannot be claimed to act as medicines.

Questions to ask before taking a dietary supplement:

  1. Do I really need it?
    1. If you follow a healthy, balanced diet, you should be getting all of your nutrition from your food. If this is the case, a dietary supplement may not actually do anything for you.
  2. Should I talk to my doctor about taking vitamin/mineral supplements?
    1. Yes, you should always talk to your doctor about taking anything new. Some supplements can cause adverse side effects if taken with other medicines, if you have a pre-existing condition, or if taken in the wrong dose.
  3. Where can I find scientifically sound information about my supplements?
    1. You should always start with your doctor. You can find additional information from the FDA, MedlinePlus, and the NIH.
  4. What should I do if I suspect my supplement is causing a negative side effect?
    1. First you should stop taking the supplement and consult your doctor. You can report adverse side effects to the FDA here.

Dietary Supplements for Weight Loss

The proven ways to lose weight are healthful eating, cutting calories, and physical activity. Some weight loss supplements offer an easier alternative to drastic lifestyle changes.

It can be difficult to gauge whether or not a supplement will work. Some ingredients may have certain effects, but work differently when mixed with other ingredients. Below is a table of common ingredients and their effects from the NIH.


IngredientDoes it work?Is it safe?
Bitter OrangeBitter orange might slightly increase the number of calories you burn, and might slightly reduce your appetite, but whether it can help you lose weight is unknown.Bitter orange might not be safe. Supplements with this ingredient can cause chest pain, anxiety, a faster heart rate, and high blood pressure.
CaffeineWeight-loss dietary supplements with caffeine might help you lose a little weight or gain a little less over time, but when you use it regularly you can develop a tolerance which can lessen its effects.Caffeine is safe at low does, though it may make you feel nervous, jittery, and shaky. It can affect your sleep. At doses above about 400 mg per day it can cause nausea, vomiting, rapid heartbeat, and seizures. Combining it with other stimulants can increase its effects.
CalciumCalcium probably does not help you lose weight or prevent you from gaining weight.Calcium is safe in the recommended amounts of 1,000-1,200 mg/day for adults. Too much can cause constipation and decrease your body's absorbtion of iron and zinc. Too much calcium from supplements can also increase your risk of kidney stones.
ChitosanChitosan binds only a tiny amount of fat, not enough to help you lose much weight.It seems to be safe, but can cause flatulence, bloating, mild nausea, constipation, indigestion, and heartburn. If you're allergic to shellfish, you could have an allergic reaction to chitosan.
ChromiumChromium might help you lose a very small amount of weight and body fat.Chromium in food and supplements is safe at recommended amounts, which range from 20 to 35 mg/day for adults. In larger amounts it can cause watery stools, headache, weakness, nausea, vomiting, constipation, dizziness, and hives.
Cola (or kola) nut (see caffeine)

Coleus forskholiiForskolin, made from the rots of the coleus forskohlii, hasn't been studied much, but so far it has no effect on body weight or appetite.Forskolin seems to be safe, but people have taken it only for a few weeks in the studies done to date.
Conjugated linoleic acid (CLA)CLA may help you lose a very small amount of weight and body fat over a year.CLA appears to be fairly safe. Though it can cause an upset stomach, constipation, diarrhea, loose stools, and indigestion. In some people it can decrease HDL, 'good cholesterol', and increase your risk for insulin resistance.
Ephedra/ma huangEphedra may help you lose weight over the short term but there are no known long-term effects.Ephedra is not safe. It can cause nausea, vomiting, anxiety, mood changes, high blood pressure, abnormal heartbeat, stroke, seizures, heart attack, and even death.
FucoxanthinFucoxanthin may help you lose weight, though it has only been studied as a weight loss aid in animals.Fucoxanthin seems safe, but has not been studied enough to know for sure.
Garcinia cambogiaGarcinia cambogia has little to no effect on weight loss.It seems to be safe, but can cause headache, nausea, and symptoms in the upper respiratory tract, stomach, and intestines. Some people taking it developed liver damage, but experts don't know if this ingredient was responsible.
GlucomannanGlucomannan has little to no effect on weight loss, but might help lower total cholesterol, LDL ('bad') cholesterol, triglyceride, and blood sugar levels.Most forms of glucomanan appear to be safe. When used for a short time it can cause loose stools, flatulence, diarrhea, constipation, and abdominal discomfort. Its effects after a longer time are unknown. In tablet form it can block the esophagus, which is a serious problem.
Green coffee bean extractGreen coffee bean extract may help you lose a small amount of weight.The safety has not been studied. It may cause headache and urinary tract infection. It contains caffeine.
Green tea and green tea extractGreen tea may help you lose weight, but only slightly.Drinking green tea is safe, but taking green tea extract might not be. It can cause nausea, constipation, abdominal discomfort, and increased blood pressure. It has also been linked to liver damage.
Guar gumGuar gum probably does not make you lose weight.It seems to be safe when taken with enough fluid. It can cause abdominal pain, flatulence, diarrhea, nausea, and cramps.
Guarana (see caffeine)

HoodiaThere hasn't been uch research, but it probably won't help you eat less or lose weight. Some analyses showed that "hoodia" supplements contained little or no actual hoodia.Hoodia might not be safe. it can cause rapid heart rate, increased blood pressure, headache, dizziness, nausea, and vomiting.
Mate (see caffeine)

PyruvatePyruvate in supplements might help you lose a small amount of weight.Pyruvate's safety hasn't been well studied. It can cause gas, bloating, diarrhea, and rumbling noises in the intestines (due to gas).
Raspberry ketoneRaspberry ketone has not been studied alone as a weight-loss aid, only in combination with other ingredients. Its effects are unknown.It has not been studied enough to determine its safety.
White kidney bean/bean podWhite kidney bean/bean pod extract (Phaselous vulgaris) might help you lose a small amount of weight and body fat.It seems fairly safe, but can cause headaches, soft stools, flatulence, and constipation.
Yerba mate (see caffeine)

YohimbeYohimbe doesn't help you lose weight.Yohimbe might not be safe. Only use with guidance from your health care provider because the side effects can be severe. It can cause headaches, high blood pressure, anxiety, agitation, rapid heartbeat, heart attack, heart failure, and even death.