Caffeine Content of Commonly Purchased Weight Loss and Sports
Performance Enhancing Dietary Supplements
A Schweitzer
1
, C Zhao
1
, KW Andrews
1
, J Holden
1
, J Roseland
1
, M Brandt
2
, J Woo
2
, J Dwyer
3
, M F Picciano
3
, LG Saldanha
3
,K Fisher
3
,J Betz
3
1
Nutrient Data Laboratory, ARS, USDA, Beltsville, MD
2
Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD
3
Office of Dietary Supplements, National Institutes of Health, Bethesda, MD
Abstract
Abstract
Consumers who require dietary caffeine restrictions may obtain information on caffeine
intake of food and beverages from NDL’s online searchable database:
http://www.nal.usda.gov/fnic/foodcomp/search. Additionally, consumers should be
aware that dietary supplements might contain caffeine. As part of the collaborative effort
to develop an analytically validated Dietary Supplement Ingredient Database (DSID),
the Nutrient Data Laboratory of USDA evaluated the caffeine content of 63 dietary
supplement products commonly marketed for weight loss or sports performance.
Learning Outcome:
Dietitians and healthcare professionals will recognize dietary
supplements which contain caffeine and apply this knowledge when counseling clients.
Methods:
Caffeine-containing dietary supplements were selected when labels listed one
or more of these ingredients: caffeine, guarana, yerba mate, cocoa, kola, tea. Samples
were analyzed with blinded standard reference materials for caffeine content by high
performance liquid chromatography. Expected daily intake of caffeine from the use of
the supplements was calculated using claimed values and analytical values along with
maximum recommended label amounts. Results:
Laboratory analysis of 63 products
showed a range of 0 - 204 mg caffeine/pill. Among 63 products analyzed, 33 had a label
claim for caffeine content. Of these, 88% had a mean analyzed value within 20% of the
claimed content. If taken at maximum recommended label amounts, 52% of the
products provided >200 mg caffeine/day. Conclusion:
Although the caffeine content of
dietary supplements is not always listed on the label, these products can provide as much
or more caffeine than a cup of brewed coffee. Application:
Dietitians and health care
professionals can use the list of caffeine-containing ingredients and the caffeine content
of dietary supplements provided in this project to counsel consumers who require
caffeine restriction. Funded through ODS/NIH Y4-HV-0051.
Agricultural
Research
Service
Introduction
Introduction
Using NDL’s online searchable database consumers can determine the caffeine content
of many foods and beverages. Brewed coffee, for example, contains 95 mg of caffeine
per 8 fluid ounces. Similar information for dietary supplements has not been available
for consumers who may want to track their caffeine consumption. Caffeine (1,3,7-
trimethylxanthine) is often added to dietary supplements to increase energy and suppress
appetite. Consumers, as well as their health care providers, may be unaware that these
supplements can contain caffeine, even if caffeine is not listed as an ingredient. The key
terms listed in Table 1 were used to identify dietary supplement products containing
caffeine for this study. As a part of a collaborative effort to develop analytical values for
an ingredient database of dietary supplements, the caffeine content in over 60 dietary
supplements was evaluated.
Methods and Materials
Methods and Materials
Because sports and weight loss supplements represent the segment of the dietary supplement
market that is most likely to contain caffeine, 63 weight loss and sports performance
enhancing dietary supplement products were selected. The sample of products was drawn
according to retail channel, stratified by 2001 market data from the Nutrition Business
Journal
1
. Products were chosen based upon the market share for four categories: 1) health
food/natural foods and vitamin stores (30.1%, n=18); 2) traditional supermarkets, grocery
stores, drug stores and mass merchandisers (25.4% n=15); 3) multi-level marketers and direct
(internet, catalog) sales (41.3% n=25); and 4) practitioners (3.2% n=2). For the categories
with n>2, top-selling products were identified to be sampled. Additional samples were
randomly selected.
Three lots for each product were planned for purchase over a 9 month period. Blinded
samples and reference material were sent to an independent laboratory for high performance
liquid chromatography analysis of caffeine. Daily caffeine intake from each supplement was
calculated using claimed and analytical values, along with maximum number of pills per
serving and per day based on product label information.
Results
Results
1
Nutrition Business Journal http://www.nutritionbusiness.com (accessed January 29 2004).
Of the 63 products, 15 products were re-formulated or had label changes during the 9 month
study, and therefore 3 lots of the original product were not available. However, only 6 of the
15 re-formulated products had changes to caffeine-containing ingredients. For the purposes of
this study, the reformulations that did not affect caffeine ingredients were considered three lot
products. Another 16 of the 63 products did not have 3 lots in this study because the product
was discontinued or a different lot was not available. Laboratory analysis showed product
means ranging from 0 – 204 mg caffeine/ pill. Of the 33 products with a quantifiable label
claim for caffeine, 88% showed a mean analytical value within 20% of the claim (Figure 1).
Table 1. Caffeine Containing Dietary Supplement Ingredients
Figure 2. Caffeine Content Per Serving of
Dietary Supplements (n=63)
Figure 3. Potential Daily Intake of Caffeine
from Dietary Supplements (n=63)
Figures 2 and 3 show caffeine/serving and caffeine/day respectively for supplements
with and without a caffeine claim. Seventeen of the products without a caffeine claim in
the 0-100 mg/serving group had less than 50 mg caffeine/serving and 5 products had 50-
100 mg caffeine/serving. In the 0-100 mg/day grouping of the products without a
caffeine claim, 15 products would provide less than 50 mg caffeine/day and 3 products
would provide 50-100 mg caffeine/day if taken at maximum recommended serving sizes
and servings/day. Four of the products identified caffeine content based on a cup of
coffee. For those products with a coffee claim, results of caffeine analysis per pill are
presented in Figure 4.
Conclusions
Conclusions
1. If taken at maximum recommended label amounts, 52% of the products studied would
provide >200 mg of caffeine/day, which is more caffeine than 2 cups of brewed coffee.
2. When counseling consumers to avoid caffeine, dietitians and other healthcare providers
should use the list of caffeine-containing ingredients and synonyms in Table 1.
3. 73% of products without a quantifiable caffeine claim contained the amount of caffeine
per serving, equal to or less than a cup of coffee. When potential daily caffeine intake
was calculated for these products, 60% would provide the amount of caffeine equal to or
less than a cup of coffee per day.
Ingredient Synonyms
guarana
paullinia cupan
a
yerba mate
Mate, Ilex paraguariensis
green tea
black tea
Camellia Sinesis, Thea
Sinesis, Camellia
kola nut
Cola Seeds, Cola nitida
coffee beans
coffea
cocoa
cacao, Theobroma cacao
1
8
7
5
4
5
3
18
33
1
22
1
0
2
4
6
8
10
12
14
16
18
20
0-100 101-200 201-300 301-400 401-500 501-600 >600
Caffeine amount (mg/day)
Number of dietary supplements
products with caffeine claim
products without caffeine claim
Figure 1. Dietary Supplement Caffeine Levels: Difference
Between Analytical Value and Label Claim
-80%
-60%
-40%
-20%
0%
20%
40%
60%
80%
Products (n=33)
Percent difference from
caffeine claim
Figure 4. Caffeine Content of Products with
Claims Based on a Cup of Coffee
Products with claims (cups of coffee/pill)
P
r
o
d
u
c
t
1
(
1
/
2
c
u
p
)
P
r
o
d
u
c
t
2
(
2
/
3
c
u
p
)
P
r
o
d
u
c
t
3
(
1
c
u
p
)
P
r
o
d
u
c
t
4
(
1
c
u
p
)
Analyzed caffeine mg/pill
0
20
40
60
80
100
120
140
8
18
7
22
5
3
0
5
10
15
20
25
0-100 101-200 201-300
Caffeine amount (mg/serving)
Number of dietary supplements
Products with caffeine claim
Products without caffeine claim
