Background
- Aloe grows in hot, dry climates and is cultivated across subtropical regions worldwide, notably in southern border regions of Texas, New Mexico, Arizona, and California.
- The bioactive substances in aloe vera have been associated with anti-inflammatory, immunomodulatory, antibacterial, antifungal, antiviral, antiproliferative, antidiabetic, laxative, wound healing, moisturizing, anti-aging, and skin protective activities1.
Safety
- Toxicology. It is likely safe to use aloe vera gel or extract topically for pain and inflammation, skin wounds, psoriasis, frostbite injury, burns, and HPV I infections (cold sores)2. Long-term ingestion of aloe latex is likely unsafe due to the theoretical risk of dehydration and electrolyte imbalance and the reported effective treatment is oral or intravenous fluid/electrolyte replacement2.
- Adversary effects
- Cardiovascular: In theory, long-term intake of aloe latex may potentially increase the risk of arrhythmia, according to anecdotal reports of potassium depletion and the laxative properties of aloe’s laxative properties2.
- Dermatologic: Topical use of aloe may not be recommended for postoperative incision healing because of delayed healing in one trial3. Photodermatitis to aloe vera has been reported4. A case of aloe-induced Henoch–Schönlein purpura was reported5. Patients undergoing dermabrasion or chemical peels should avoid using topical aloe vera in the first weeks after surgery to prevent the risk of severe dermatitis6. Drying up of the skin on the test areas, stinging, soreness or fissures were reported in one clinical trial of aloe vera7.
- Endocrine: The impact of oral aloe on human blood glucose levels is still uncertain, but caution is advised for patients using antihyperglycemic medications2. A reported case suggested a link between aloe vera and thyroid dysfunction8.
- Gastrointestinal: Long-term use of anthranoid-containing laxatives could increase the risk of colorectal cancer9.
- Hematologic: A poorly documented case report describes a surgical patient experiencing intraoperative bleeding after receiving sevoflurane anesthesia and ingesting oral aloe10.
- Hepatologic: 8 cases of acute hepatitis due to oral ingestion of aloe vera compound have been reported worldwide and all of them showed improved conditions after stopping taking aloe11.
- Renal: A patient developed an ammonium acid urate stone after 12 years of using laxatives (bisacodyl, sennoside, and aloe extract)12.
- Precautions/warnings/contradictions
- Patients with diabetes, glucose intolerance, or those taking glucose-lowering agents should monitor their blood glucose level when using oral aloe products2.
- Patients with renal insufficiency, cardiac disease, or electrolyte abnormalities should avoid oral aloe latex due to the risk of hypokalemia2.
- Patients with ileus, acute surgical abdomen, bowel obstruction, fecal impaction or appendicitis should avoid oral aloe latex2.
- Aloe vera injections should be avoided which have been linked with four cases of death under unclear circumstances2.
- The high mucilage content in oral aloe may interfere with the absorption of foods or orally administered drugs2.
- Oral aloe latex may influence laboratory results for serum potassium levels, serum glucose levels, and thyroid panel tests2.
- Pregnancy and lactation
- Aloe latex should not be used during breastfeeding because its safety and efficacy have not been eastablished13.
- Aloe vera gel is probably effective for relieving breast pain or irritation in lactating women14, however, it should be washed off before nursing the infant because the taste might affect nursing or lead to diarrhea in infants15.
- Aloe vera/drug interactions
- Digoxin, digitoxin. Aloe latex-induced hypokalemia may interfere with cardiac glycosides or other antiarrhythmic agents2.
- Insulin. Concurrent use of insulin with oral aloe latex may increase hypoglycemic effects16-17 and cause potassium depletion2.
- Laxatives. Concurrent use of oral aloe latex with other laxatives could potentially worsen hypokalemia, dehydration, metabolic alkalosis, or other electrolyte abnormalities2.
- Non-potassium sparing diuretics. Hypokalemia may worsen by concomitant use of oral aloe latex and thiazide diuretics2.
- Oral corticosteroids. Hypokalemia may worsen by concomitant use of oral aloe latex and steroids2.
- Oral hypoglycemic agents. Concurrent use of oral aloe with glucose-lowering agents may increase hypoglycemic effects16-17.
- Sevoflurane. A poorly documented case reported excess bleeding in a patient taking the anesthetic agent sevoflurane and oral aloe simultaneously10.
- Thyroid hormones. Aloe vera has been associated with thyroid dysfunction8.
- Topical hydrocortisone. Concurrent use of aloe vera with topical hydrocortisone may increase absorption of hydrocortisone based on limited evidence18.
- Zidovudine (also known as azidothymidine). Oral aloe products may increase azidothymidine levels according to preliminary reports2.
- Aloe vera/herb or supplement interactions
- Hypoglycemic agents. Concurrent use of glucose-lowering agents with oral aloe may potentially increase hypoglycemic effects according to preliminary human trials16-17.
- Laxative herbs. In theory, combing oral aloe latex with other laxatives may worsen hypokalemia, dehydration, metabolic alkalosis, or other electrolyte abnormalities2.
- Licorice root (also known as glycyrrhiza glabra L). Concurrent use of oral aloe latex with licorice root may worsen hypokalemia2.
- Thyroid agents. Aloe has been associated with thyroid dysfunction8.
- Vitamins (C and E). Aloe may decrease the absorption of vitamins C and E19.
Effectiveness
- Probably effective
- Burn wounds.
- Plague and gingivitis: aloe vera mouthwash is comparable to chlorhexidine in reducing gingival inflammation but inferior to chlorhexidine in reducing plaque.
- Topical use of aloe gel is generally well tolerated. However, there have been occasional reports of burning, itching, and eczema with topical use of aloe gel. Oral use of aloe latex can cause abdominal pain and cramps. Oral consumption of aloe leaf extracts (for as little as 3 weeks and as long as 5 years) has been related to cases of acute hepatitis.
- Animal studies have noted an association between aloe vera leaf extract taken orally and gastrointestinal cancer in rats and mice; however, concerns were expressed about the differences in the product used in that study and those commonly used by consumers. Thus, more research is needed to assess the relevance to human health.
- Overuse of aloe latex may increase the risk of adverse effects from the drug digoxin, used for some heart problems.
- Aloe—both in gel and latex form—when taken by mouth may be unsafe during pregnancy and while breastfeeding.
References
- Radha MH, Laxmipriya NP. Evaluation of biological properties and clinical effectiveness of Aloe vera: A systematic review. J Tradit Complement Med. 2014 Dec 23;5(1):21-6. doi: 10.1016/j.jtcme.2014.10.006. PMID: 26151005; PMCID: PMC4488101.
- Ulbricht C, Armstrong J, Basch E, Basch S, Bent S, Dacey C, Dalton S, Foppa I, Giese N, Hammerness P, Kirkwood C, Sollars D, Tanguay-Colucci S, Weissner W. An evidence-based systematic review of Aloe vera by the natural standard research collaboration. J Herb Pharmacother. 2007;7(3-4):279-323. doi: 10.1080/15228940802153339. PMID: 18928148.
- Schmidt JM, Greenspoon JS. Aloe vera dermal wound gel is associated with a delay in wound healing. Obstet Gynecol. 1991 Jul;78(1):115-7. PMID: 2047051.
- Domínguez-Soto L. Photodermatitis to aloe vera. Int J Dermatol. 1992 May;31(5):372. doi: 10.1111/j.1365-4362.1992.tb03971.x. PMID: 1587675.
- Kim EJ, Kim HJ, Kim SG, Lee YS, Oh JE, Seo JW, Koo JR, Noh JW. Aloe-induced Henoch-Schonlein purpura. Nephrology (Carlton). 2007 Feb;12(1):109. doi: 10.1111/j.1440-1797.2006.00752.x. PMID: 17295672.
- Hunter D, Frumkin A. Adverse reactions to vitamin E and aloe vera preparations after dermabrasion and chemical peel. Cutis. 1991 Mar;47(3):193-6. PMID: 2022130.
- Paulsen E, Korsholm L, Brandrup F. A double-blind, placebo-controlled study of a commercial Aloe vera gel in the treatment of slight to moderate psoriasis vulgaris. J Eur Acad Dermatol Venereol. 2005 May;19(3):326-31. doi: 10.1111/j.1468-3083.2004.01186.x. PMID: 15857459.
- Pigatto PD, Guzzi G. Aloe linked to thyroid dysfunction. Arch Med Res. 2005 Sep-Oct;36(5):608. doi: 10.1016/j.arcmed.2005.03.022. PMID: 16099348.
- Siegers CP, von Hertzberg-Lottin E, Otte M, Schneider B. Anthranoid laxative abuse–a risk for colorectal cancer? Gut. 1993 Aug;34(8):1099-101. doi: 10.1136/gut.34.8.1099. PMID: 8174962; PMCID: PMC1374362.
- Lee A, Chui PT, Aun CS, Gin T, Lau AS. Possible interaction between sevoflurane and Aloe vera. Ann Pharmacother. 2004 Oct;38(10):1651-4. doi: 10.1345/aph.1E098. Epub 2004 Aug 3. PMID: 15292490.
- Lee J, Lee MS, Nam KW. Acute toxic hepatitis caused by an aloe vera preparation in a young patient: a case report with a literature review. Korean J Gastroenterol. 2014 Jul;64(1):54-8. doi: 10.4166/kjg.2014.64.1.54. PMID: 25073673.
- Kato Y, Hou K, Saga Y, Yamaguchi S, Yachiku S, Kawakami N. [Ammonium acid urate stone due to laxative abuse: a case report]. Hinyokika Kiyo. 2004 Nov;50(11):799-803. Japanese. PMID: 15628542.
- Kopec K. Herbal medications and breastfeeding. J Hum Lact. 1999 Jun;15(2):157-61. doi: 10.1177/089033449901500219. PMID: 10578793.
- Maleki A, Youseflu S. The Effectiveness of Aloe Vera on Relief of Irritation and Nipple Pain in Lactating Women: Systematic Review and Meta-Analysis. Obstet Gynecol Int. 2022 Nov 7;2022:7430581. doi: 10.1155/2022/7430581. PMID: 36388847; PMCID: PMC9663246.
- Larimore WL, Petrie KA. Drug use during pregnancy and lactation. Prim Care. 2000 Mar;27(1):35-53. doi: 10.1016/s0095-4543(05)70147-0. PMID: 10739456.
- Yongchaiyudha S, Rungpitarangsi V, Bunyapraphatsara N, Chokechaijaroenporn O. Antidiabetic activity of Aloe vera L. juice. I. Clinical trial in new cases of diabetes mellitus. Phytomedicine. 1996 Nov;3(3):241-3. doi: 10.1016/S0944-7113(96)80060-2. PMID: 23195077.
- Bunyapraphatsara N, Yongchaiyudha S, Rungpitarangsi V, Chokechaijaroenporn O. Antidiabetic activity of Aloe vera L. juice II. Clinical trial in diabetes mellitus patients in combination with glibenclamide. Phytomedicine. 1996 Nov;3(3):245-8. doi: 10.1016/S0944-7113(96)80061-4. PMID: 23195078.
- Davis RH, Parker WL, Murdoch DP. Aloe vera as a biologically active vehicle for hydrocortisone acetate. J Am Podiatr Med Assoc. 1991 Jan;81(1):1-9. doi: 10.7547/87507315-81-1-1. PMID: 1993971.
- Davis RH, Parker WL, Murdoch DP. Aloe vera as a biologically active vehicle for hydrocortisone acetate. J Am Podiatr Med Assoc. 1991 Jan;81(1):1-9. doi: 10.7547/87507315-81-1-1. PMID: 1993971.