Aloe (Aloe vera)
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| Aloe |
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Transparent gel from the pulp of the meaty leaves of Aloe vera
has been used topically for thousands of years to treat wounds, skin
infections, burns, and numerous other dermatologic conditions. Dried latex
from the inner lining of the leaf has traditionally been used as an oral
laxative.
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There is strong scientific evidence in support of the laxative properties of
aloe latex, based on the well-established cathartic properties of
anthroquinone glycosides (found in aloe latex). However, aloe's therapeutic
value compared with other approaches to constipation remains unclear.
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There is promising preliminary support from laboratory, animal, and human
studies that topical aloe gel has immunomodulatory properties which may
improve wound healing and skin inflammation.
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Acemannan, Aloe africana , Aloe arborescens Miller,
Aloe barbadensis , Aloe capensis , Aloe
ferox , aloe latex, aloe mucilage, Aloe perfoliata ,
Aloe perryi Baker, Aloe saponaria , Aloe
spicata , Aloe vulgari , Barbados aloe, bitter
aloe, burn plant, Cape aloe, Carrisyn, hirukattali, Curaçao aloe, elephant's
gall, first-aid plant, Ghai kunwar, Ghikumar, Hsiang-Dan, jelly leek, kumari,
lahoi, laloi, lily of the desert, Lu-Hui, medicine plant, Mediterranean aloe,
miracle plant, mocha aloes, musabbar, natal aloes, nohwa, plant of
immortality, plant of life, rokai, sabilla, Savila, Socotrine aloe, subr, true
aloe, Venezuela aloe, Za'bila, Zanzibar aloe.
These uses have been tested in humans or animals. Safety
and effectiveness have not always been proven. Some of these conditions are
potentially serious, and should be evaluated by a qualified healthcare provider.
| Uses based on scientific evidence |
Grade* |
| Constipation (laxative)
Dried latex from the inner lining of aloe leaves has been used
traditionally as a laxative taken by mouth. Although few studies have
been conducted to assess this effect of aloe in humans, the laxative
properties of aloe components such as aloin are well supported by
scientific evidence. A combination herbal remedy containing aloe was
found to be an effective laxative, although it is not clear if this
effect was due to aloe or to other ingredients in the product. Further
study is needed to establish dosing and to compare the effectiveness and
safety of aloe with other commonly used laxatives.
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A |
| Genital herpes
Limited evidence from human studies suggests that extract from Aloe
vera in a hydrophilic cream may be an effective treatment of
genital herpes in men (better than aloe gel or placebo). Additional
research is needed in this area before a strong recommendation can be
made.
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B |
| Psoriasis vulgaris
Early evidence suggests that extract from aloe in a hydrophilic cream
may be an effective treatment of psoriasis vulgaris. Additional research
is needed in this area before a strong recommendation can be made.
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B |
| Seborrheic dermatitis (seborrhea, dandruff)
Early study of aloe lotion suggests effectiveness for treating
seborrheic dermatitis when applied to the skin. Further study is needed
in this area before a strong recommendation can be made.
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B |
| Cancer prevention
There is preliminary evidence that oral aloe may reduce the risk of
developing lung cancer. Further study is needed in this area to clarify
if it is aloe itself or other factors that may cause this benefit.
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C |
| Canker sores (aphthous stomatitis)
There is weak evidence that treatment of recurrent aphthous ulcers of
the mouth with aloe gel may reduce pain and increase the amount of time
between the appearance of new ulcers. Further study is needed before a
recommendation can be made.
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C |
| Diabetes (type 2)
Study results are mixed. More research is needed to explore the
effectiveness and safety of aloe in diabetics.
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C |
| HIV infection
Without further human trials, the evidence cannot be considered
convincing either in favor or against this use of aloe.
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C |
| Skin burns
Preliminary evidence suggests that aloe may be effective in promoting
healing of mild to moderate skin burns. Further study is needed in this
area.
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C |
| Ulcerative colitis
There is limited but promising research of the use of oral aloe vera in
ulcerative colitis (UC), compared to placebo. It is not clear how aloe
vera compares to other treatments used for UC.
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C |
| Wound healing
Study results of aloe on wound healing are mixed with some studies
reporting positive results and others showing no benefit or potential
worsening of the condition. Further study is needed, since wound healing
is a popular use of topical aloe.
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| Mucositis
There is preliminary evidence that oral aloe vera does not prevent or
improve mucositis (mouth sores) associated with radiation therapy.
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D |
| Pressure ulcers
One well-designed human trial found no benefit of topical acemannan
hydrogel (a component of aloe gel) in the treatment of pressure ulcers.
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| Radiation dermatitis
Reports in the 1930s of topical aloe's beneficial effects on skin after
radiation exposure lead to widespread use in skin products. Currently,
aloe gel is sometimes recommended for radiation-induced dermatitis,
although scientific evidence suggests a lack of benefit in this area.
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D |
*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.
Grading rationale
Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often
have not been thoroughly tested in humans, and safety and effectiveness have
not always been proven. Some of these conditions are potentially serious, and
should be evaluated by a qualified healthcare provider.
Alopecia (hair loss), Alzheimer's disease, antimicrobial, antioxidant,
arthritis, asthma, bacterial skin infections, bowel disorders, chronic fatigue
syndrome, chronic leg wounds, congestive heart failure, damaged blood vessels,
elevated cholesterol or other lipids, frostbite, heart disease prevention,
hepatitis, inflammatory bowel disease (IBS), kidney or bladder stones, leukemia,
lichen planus, Merkel cell carcinoma, parasitic worm infections, protection
against some chemotherapy side effects, scratches or superficial wounds of the
eye, stomach ulcers, systemic lupus erythematosus (SLE), tic douloureux,
untreatable tumors, vaginal contraceptive, yeast infections of the skin.
The below doses are based on scientific research,
publications, traditional use, or expert opinion. Many herbs and supplements
have not been thoroughly tested, and safety and effectiveness may not be proven.
Brands may be made differently, with variable ingredients, even within the same
brand. The below doses may not apply to all products. You should read product
labels, and discuss doses with a qualified healthcare provider before starting
therapy.
Adults (18 years and older)
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Pure Aloe vera gel is often used liberally on the skin.
Creams and lotions are also available. There are no reports that using aloe on
the skin causes absorption of chemicals into the body that may cause
significant side effects. Skin products are available that contain aloe alone
or aloe combined with other active ingredients.
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The dose often recommended constipation is the minimum amount to maintain a
soft stool, typically 0.04-0.17 gram of dried juice (corresponds to 10-30
milligrams hydroxyanthraquinones) by mouth. As an alternative, in combination
with celandin (300 milligrams) and psyllium (50 milligrams), 150 milligrams of
the dried juice per day of aloe has been found effective as a laxative in
research.
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Cases of death have been associated with Aloe vera
injections under unclear circumstances. Oral or injected use is not
recommended due to lack of safety data.
Children (younger than 18 years)
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Topical (skin) use of aloe gel in children is common and appears to be well
tolerated. However a dermatologist and pharmacist should be consulted before
starting therapy.
The U.S. Food and Drug Administration does not strictly
regulate herbs and supplements. There is no guarantee of strength, purity or
safety of products, and effects may vary. You should always read product labels.
If you have a medical condition, or are taking other drugs, herbs, or
supplements, you should speak with a qualified healthcare provider before
starting a new therapy. Consult a healthcare provider immediately if you
experience side effects.
Allergies
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People with known allergy to garlic, onions, tulips, or other plants of the
Liliaceae family may have allergic reactions to aloe. Individuals using aloe
gel for prolonged times have developed allergic reactions including hives and
eczema-like rash.
Side Effects and Warnings
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The use of aloe on surgical wounds has been reported to slow healing and may
cause redness and burning after aloe juice was applied to the face after a
skin-peeling procedure (dermabrasion). Application of aloe prior to sun
exposure may lead to rash in sun-exposed areas.
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The use of aloe or aloe latex by mouth for laxative effects can cause cramping
or diarrhea. Use for over seven days may cause dependency or worsening of
constipation after the aloe is stopped. Ingestion of aloe for over one year
has been reported to increase the risk of colorectal cancer. Individuals with
severe abdominal pain, appendicitis, ileus (temporary paralysis of the bowel),
or a prolonged period without bowel movements should not take aloe. There is a
report of hepatitis (liver inflammation) with the use of oral aloe.
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Electrolyte imbalances in the blood, including low potassium levels, may be
caused by the laxative effect of aloe. This effect may be greater in people
with diabetes or kidney disease. Low potassium levels can lead to abnormal
heart rhythms or muscle weakness. People with heart disease, kidney disease,
or electrolyte abnormalities should not take aloe by mouth. Healthcare
professionals should monitor for changes in potassium and other electrolytes
in individuals who take aloe by mouth for more than a few days.
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Aloe taken by mouth may lower blood sugar levels. Caution is advised in
patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or
supplements that affect blood sugar. Serum glucose levels may need to be
monitored by a healthcare professional, and medication adjustments may be
necessary.
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Avoid aloe vera injections, which have been associated with cases of death
under unclear circumstances.
Pregnancy and Breastfeeding
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Although topical (skin) use of aloe is unlikely to be harmful during pregnancy
or breastfeeding, oral (by mouth) use is not recommended due to theoretical
stimulation of uterine contractions. It is not known whether active
ingredients of aloe may be present in breast milk. The dried juice of aloe
leaves should not be consumed by breastfeeding mothers.
Most herbs and supplements have not been thoroughly
tested for interactions with other herbs, supplements, drugs, or foods. The
interactions listed below are based on reports in scientific publications,
laboratory experiments, or traditional use. You should always read product
labels. If you have a medical condition, or are taking other drugs, herbs, or
supplements, you should speak with a qualified healthcare provider before
starting a new therapy.
Interactions with Drugs
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Aloe taken by mouth may lower blood sugar levels. Caution is advised when
taken with medications that may also lower blood sugar. Patients taking drugs
for diabetes by mouth or insulin should be monitored closely by a qualified
healthcare professional. Medication adjustments may be necessary. In addition,
insulin may add to the decrease in blood potassium levels that can occur with
aloe.
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Due to lowering of potassium levels that may occur when aloe is taken by
mouth, the effectiveness of heart medications such as digoxin and digitoxin,
and of other medications used for heart rhythm disturbances, may be reduced.
The risk of adverse effects may be increased with these medications due to low
potassium levels.
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Caution should be used in patients taking loop diuretics, such as Lasix® (furosemide),
that increase the elimination of both fluid and potassium in the urine.
Combined use may increase the risk of potassium depletion and of dehydration.
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Use of aloe with laxative drugs may increase the risk of dehydration,
potassium depletion, electrolyte imbalance, and changes in blood pH.
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Application of aloe to skin may increase the absorption of steroid creams such
as hydrocortisone. In addition, oral use of aloe and steroids such as
prednisone may increase the risk of potassium depletion.
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There is one report of excess bleeding in a patient undergoing surgery
receiving the anesthetic drug sevoflurane, who was also taking aloe by mouth.
It is not clear that aloe or this specific interaction was the cause of
bleeding.
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Preliminary reports suggest that levels of AZT, a drug prescribed in HIV
infection, may be increased by intake of aloe.
Interactions with Herbs and Dietary Supplements
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Based on the laxative properties of oral aloe, prolonged use may result in
potassium depletion. This may be worsened by the use of licorice root.
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Theoretically, use of oral aloe and other laxative herbs may increase the risk
of dehydration, potassium depletion, electrolyte imbalance, and changes in
blood pH.
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Oral aloe can reduce blood sugar. Caution is advised when using herbs or
supplements that may also lower blood sugar. Blood glucose levels may require
monitoring, and doses may need adjustment.
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Aloe may increase the absorption of vitamin C and vitamin E.