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Research · Supplements

Aloe vera

Oral aloe lowered fasting glucose and HbA1c in three meta-analyses of small trials, and improved IBS symptoms in a pooled analysis of 3 trials. Topical aloe shortened second-degree burn healing by about 4 days and reduced radiation dermatitis. Psoriasis trials conflict. Whole-leaf extract caused colon tumors in rats, and case reports describe liver injury.

Add to Bio HackChecked 2026-11-12
Status
Dietary supplement, food and cosmetic ingredient in the US. Since 2002 the FDA has not allowed aloe as an ingredient in over-the-counter laxative drugs.
Also called
Aloe barbadensis Miller, aloe gel, aloe juice, aloe latex, whole-leaf aloe, aloin, aloe-emodin, acemannan, aloe sterol, Aloe ferox
Taken for
ulcerative colitis, constipation, IBS, blood sugar, diabetes, burns, wound healing, skin health, psoriasis, radiation skin reactions, inflammation, skin aging, wrinkles, skin hydration, skin elasticity

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help7

Reported risks4

What people take it for, and what was found

Shown to help7

Strong

Blood sugar, oral

Shown to lower fasting glucose in adults with prediabetes or type 2 diabetes, and HbA1c in type 2 diabetes. Trials were few and varied.

The numbers and sources
Effect
Across 8 trials (470 patients), aloe vera lowered fasting plasma glucose in prediabetes (MD -0.22 mmol/L, 95% CI -0.32 to -0.12) without changing HbA1c. In type 2 diabetes, HbA1c fell (MD -11 mmol/mol, 95% CI -19 to -2) and fasting glucose fell marginally (MD -1.17 mmol/L, P 0.05) [1]. Across 5 RCTs (415 participants) with prediabetes or early untreated diabetes, fasting glucose fell by 30.05 mg/dL (95% CI -54.87 to -5.23) and HbA1c by 0.41% (95% CI -0.55 to -0.27) [2]. A third meta-analysis found fasting glucose 46.6 mg/dL lower (9 studies, 283 people) and HbA1c 1.05% lower (5 studies, 89 people) than baseline [3].
Population
Adults with prediabetes or type 2 diabetes [1][2][3].
Sources
[1], [2], [3]
Caveats
Heterogeneity was high and preparations varied [1]. The trials were few and of poor quality [2]. The third analysis measured change from baseline and found publication bias for fasting glucose [3].
Moderate

Irritable bowel syndrome, oral

Shown to improve IBS symptom scores and response rates over placebo in adults, across 3 small, short trials.

The numbers and sources
Effect
Across 3 RCTs (151 patients), aloe vera improved IBS symptom scores against placebo (SMD 0.41, 95% CI 0.07 to 0.75) and raised response rates (RR 1.69, 95% CI 1.05 to 2.73), with no heterogeneity (I² 0%) [4].
Population
Adults with IBS [4].
Sources
[4]
Caveats
Three small, short trials [4].
Limited

Ulcerative colitis, oral

One small trial found more clinical response on aloe gel than placebo over 4 weeks, 47% against 14%, but remission did not differ significantly.

The numbers and sources
Effect
In 44 outpatients with mild to moderate ulcerative colitis, oral aloe vera gel 100 mL twice a day for 4 weeks gave clinical remission in 30% against 7% on placebo (P 0.09) and clinical response in 47% against 14% (P < 0.05, OR 5.3, 95% CI 1.0 to 27). Histology scores fell on aloe vera. Sigmoidoscopy scores and blood markers did not differ [5].
Population
30 on aloe vera and 14 on placebo, UK [5].
Sources
[5]
Caveats
One small 4-week trial. The remission difference was not significant [5].
Limited

Constipation, oral

One trial found capsules of celandine, aloe and psyllium gave more frequent, softer bowel movements in 35 adults. Aloe's own share is unknown.

The numbers and sources
Effect
In 35 adults with chronic constipation, capsules of celandine, aloe vera and psyllium for 28 days gave more frequent and softer bowel movements and less laxative use, while placebo did not change these. Abdominal pain did not change in either group [6].
Population
35 adults [6].
Sources
[6]
Caveats
The product combined three ingredients, so aloe's share of the effect is unknown [6].
Limited

Skin hydration, elasticity and wrinkles, oral aloe sterols

Small trials found oral aloe sterols improved some skin measures, several only in subgroups. The trials came from researchers linked to the product maker.

The numbers and sources
Effect
In 64 healthy women aged 30 to 59, yogurt with aloe sterols for 12 weeks changed skin moisture, transepidermal water loss, elasticity and ultrasound collagen score against placebo [7]. In 122 healthy volunteers, a lower dose for 12 weeks reduced transepidermal water loss and raised collagen score against placebo. Hydration rose against placebo only in a subgroup with dry skin that was not planned before the study [8]. In 48 men who exposed their forearms to sunlight daily for 12 weeks, elasticity rose from baseline on aloe sterols and did not differ from placebo, except in men under 46 at week 8 [9]. In women with dry skin, aloe vera gel powder with 40 µg of aloe sterols did not change skin moisture against placebo at 8 weeks. In a subgroup aged 40 and over, mean wrinkle depth fell more than on placebo [10].
Population
64 women [7]; 122 healthy volunteers [8]; 48 men aged 30 to 59 [9]; Japanese women with dry skin [10].
Sources
[7], [8], [9], [10]
Caveats
Three of the four reports list authors at Morinaga Milk Industry, and the fourth shares those authors [7][8][9][10]. Morinaga prepared the aloe sterol product [8]. Several positive findings come from subgroups [8][9][10]. This block covers oral aloe sterols, not aloe gel applied to the skin.
Strong

Burns, topical

Shown to speed healing of second-degree burns by about 4 days compared with other topical treatments, with no difference in pain or infection.

The numbers and sources
Effect
Across 6 RCTs with healing data, aloe vera shortened wound healing time against other topical treatments (MD -3.76 days, 95% CI -5.69 to -1.84). Pain (MD -0.76 points, 95% CI -1.53 to 0.01) and infection (RR 1.10, 95% CI 0.34 to 3.59) did not differ [11]. A second meta-analysis of 4 trials (133 patients, 163 wounds) found healing 4.44 days faster (P 0.004) [12].
Population
Patients with second-degree burns [11][12].
Sources
[11], [12]
Caveats
Comparators were other topical products, often silver sulfadiazine, not placebo [11].
Moderate

Radiation skin reactions, topical

Shown to lower the risk of radiation dermatitis by about 24% in adults having radiotherapy, across 14 trials with high heterogeneity.

The numbers and sources
Effect
Across 14 RCTs (1,572 participants), aloe vera before radiotherapy lowered the risk of radiation dermatitis (RR 0.76, 95% CI 0.67 to 0.88, I² 79.8%). Grade 2 to 4 dermatitis had RR 0.44 (95% CI 0.27 to 0.74). Grade 4 did not differ (RR 0.13, 95% CI 0.02 to 1.01) [13].
Population
Adults receiving radiotherapy [13].
Sources
[13]
Caveats
Heterogeneity was high [13].

Mixed results1

Limited

Psoriasis, topical

Small trials found opposite results: one aloe cream cleared psoriasis in 25 of 30 against 2 of 30 on placebo, and another aloe gel did worse than placebo.

The numbers and sources
Effect
In 60 patients, 0.5% aloe vera extract cream for up to 4 weeks cleared psoriasis in 25 of 30 against 2 of 30 on placebo (P < 0.001) [14]. In 40 patients using a commercial aloe vera gel on one side and placebo on the other for 4 weeks, symptom scores improved in 72.5% of aloe-treated sites and 82.5% of placebo sites, in favor of placebo (P 0.0197) [15]. In 80 patients over 8 weeks, PASI fell by 7.7 on aloe vera cream and 6.6 on 0.1% triamcinolone (P 0.0237), and quality of life scores did not differ [16].
Population
Adults with mild to moderate plaque psoriasis in Pakistan [14], Denmark [15] and Thailand [16].
Sources
[14], [15], [16]
Caveats
The placebo-controlled trials point in opposite directions and tested different products [14][15].

Doses studied

The ulcerative colitis trial gave 100 mL of oral aloe vera gel twice a day for 4 weeks [5]. The psoriasis cream trial used 0.5% aloe vera extract three times a day, 5 days a week, for up to 4 weeks [14]. The oral aloe sterol trials used aloe vera gel powder with 40 µg of aloe sterols a day [10], and later about half that dose for 12 weeks [8].

Risks

Reported risks3

Limited

Colon tumors in rats from whole-leaf extract

Animal studies only: rats given whole-leaf aloe extract in drinking water had more large intestine tumors. Mice and rats at the lowest dose had none.

The numbers and sources
Effect
In 2-year National Toxicology Program studies, rats given a whole-leaf aloe vera extract at 1% and 1.5% in drinking water had significantly more adenomas and carcinomas of the large intestine than controls. No large intestine tumors occurred in mice, in control rats or in rats at 0.5%. Female rats at 1.5% had lower survival [17].
Population
Animal. F344/N rats and B6C3F1 mice, 48 per sex per group [17].
Sources
[17]
Caveats
Animal findings from extract in drinking water. The study tested a whole-leaf extract, not the inner leaf gel [17].
Moderate

FDA removal from over-the-counter laxatives

FDA ruled in 2002 that aloe could no longer be sold as an over-the-counter stimulant laxative, because the cancer and genetic toxicity data it requested were never submitted.

The numbers and sources
Effect
In 2002 the FDA ruled that aloe, including aloe extract and aloe flower extract, was "not generally recognized as safe and effective" as an over-the-counter stimulant laxative. The FDA had asked in 1998 for mutagenicity, genotoxicity and carcinogenicity data, and no data were submitted. Products labeled for laxative use with aloe were deemed misbranded from November 5, 2002 [18].
Population
US over-the-counter laxative products [18].
Sources
[18]
Caveats
The rule rests on missing safety data, not on a measured harm in people [18].
Limited

Liver injury, oral

Case reports: four women in Korea developed toxic hepatitis after weeks to months of oral aloe. In three, liver enzymes returned to normal after stopping.

The numbers and sources
Effect
Three women aged 55 to 62 developed acute toxic hepatitis after taking oral aloe preparations for months. All met RUCAM criteria, and liver enzymes returned to normal after stopping [19]. A 21-year-old woman developed acute toxic hepatitis after 4 weeks of an aloe vera preparation [20].
Population
Case reports from Korea [19][20].
Sources
[19], [20]
Caveats
Case reports give no rate, and the abstracts do not name the aloe product type.

Mixed results1

Moderate

Side effects in trials

Side effects were few and about as common as on placebo in short oral trials. In one topical gel trial, 55% reported local effects, mainly dry skin.

The numbers and sources
Effect
No aloe-related adverse events were found in the 3 IBS trials [4]. Adverse events were minor and similar to placebo in the ulcerative colitis trial [5]. In the glucose meta-analysis, only one adverse event was reported [2]. 55% of patients in the topical gel psoriasis trial reported local side effects, mainly dry skin [15].
Population
Trial participants [2][4][5][15].
Sources
[4], [5], [2], [15]
Caveats
Trials were short. The glucose review notes limited safety evidence [2].

Claims tested and not found

  1. That a commercial aloe vera gel clears psoriasis. Placebo sites improved more than aloe-treated sites over 4 weeks (P 0.0197) [15].

Sources

  1. Suksomboon N, Poolsup N, Punthanitisarn S. Effect of Aloe vera on glycaemic control in prediabetes and type 2 diabetes: a systematic review and meta-analysis. Journal of Clinical Pharmacy and Therapeutics. 2016. https://doi.org/10.1111/jcpt.12382
  2. Zhang Y, Liu W, Liu D, et al. Efficacy of Aloe Vera Supplementation on Prediabetes and Early Non-Treated Diabetic Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2016. https://doi.org/10.3390/nu8070388
  3. Dick WR, Fletcher EA, Shah SA. Reduction of Fasting Blood Glucose and Hemoglobin A1c Using Oral Aloe Vera: A Meta-Analysis. Journal of Alternative and Complementary Medicine. 2016. https://doi.org/10.1089/acm.2015.0122
  4. Hong SW, Chun J, Park S, et al. Aloe vera Is Effective and Safe in Short-term Treatment of Irritable Bowel Syndrome: A Systematic Review and Meta-analysis. Journal of Neurogastroenterology and Motility. 2018. https://doi.org/10.5056/jnm18077
  5. Langmead L, Feakins RM, Goldthorpe S, et al. Randomized, double-blind, placebo-controlled trial of oral aloe vera gel for active ulcerative colitis. Alimentary Pharmacology & Therapeutics. 2004. https://doi.org/10.1111/j.1365-2036.2004.01902.x
  6. Odes HS, Madar Z. A double-blind trial of a celandin, aloevera and psyllium laxative preparation in adult patients with constipation. Digestion. 1991. https://pubmed.ncbi.nlm.nih.gov/1800188/
  7. Tanaka M, Yamamoto Y, Misawa E, et al. Effects of Aloe Sterol Supplementation on Skin Elasticity, Hydration, and Collagen Score: A 12-Week Double-Blind, Randomized, Controlled Trial. Skin Pharmacology and Physiology. 2016. https://doi.org/10.1159/000454718
  8. Kaminaka C, Yamamoto Y, Sakata M, et al. Effects of low-dose Aloe sterol supplementation on skin moisture, collagen score and objective or subjective symptoms: 12-week, double-blind, randomized controlled trial. The Journal of Dermatology. 2020. https://doi.org/10.1111/1346-8138.15428
  9. Tanaka M, Yamamoto Y, Misawa E, et al. Aloe sterol supplementation improves skin elasticity in Japanese men with sunlight-exposed skin: a 12-week double-blind, randomized controlled trial. Clinical, Cosmetic and Investigational Dermatology. 2016. https://doi.org/10.2147/CCID.S118947
  10. Tanaka M, Misawa E, Yamauchi K, et al. Effects of plant sterols derived from Aloe vera gel on human dermal fibroblasts in vitro and on skin condition in Japanese women. Clinical, Cosmetic and Investigational Dermatology. 2015. https://doi.org/10.2147/CCID.S75441
  11. Huang YN, Chen KC, Wang JH, et al. Effects of Aloe vera on Burn Injuries: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Journal of Burn Care & Research. 2024. https://doi.org/10.1093/jbcr/irae061
  12. Sharma S, Alfonso AR, Gordon AJ, et al. Second-Degree Burns and Aloe Vera: A Meta-analysis and Systematic Review. Advances in Skin & Wound Care. 2022. https://doi.org/10.1097/01.ASW.0000875056.29059.78
  13. Wang T, Liao J, Zheng L, et al. Aloe vera for prevention of radiation-induced dermatitis: A systematic review and cumulative analysis of randomized controlled trials. Frontiers in Pharmacology. 2022. https://doi.org/10.3389/fphar.2022.976698
  14. Syed TA, Ahmad SA, Holt AH, et al. Management of psoriasis with Aloe vera extract in a hydrophilic cream: a placebo-controlled, double-blind study. Tropical Medicine & International Health. 1996. https://doi.org/10.1046/j.1365-3156.1996.d01-91.x
  15. 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. Journal of the European Academy of Dermatology and Venereology. 2005. https://doi.org/10.1111/j.1468-3083.2004.01186.x
  16. Choonhakarn C, Busaracome P, Sripanidkulchai B, Sarakarn P. A prospective, randomized clinical trial comparing topical aloe vera with 0.1% triamcinolone acetonide in mild to moderate plaque psoriasis. Journal of the European Academy of Dermatology and Venereology. 2010. https://doi.org/10.1111/j.1468-3083.2009.03377.x
  17. Boudreau MD, Mellick PW, Olson GR, et al. Clear evidence of carcinogenic activity by a whole-leaf extract of Aloe barbadensis miller (aloe vera) in F344/N rats. Toxicological Sciences. 2013. https://doi.org/10.1093/toxsci/kfs275
  18. U.S. Food and Drug Administration. Status of Certain Additional Over-the-Counter Drug Category II and III Active Ingredients. Final rule. Federal Register 67(90):31125. 2002. https://www.govinfo.gov/content/pkg/FR-2002-05-09/html/02-11510.htm
  19. Yang HN, Kim DJ, Kim YM, et al. Aloe-induced toxic hepatitis. Journal of Korean Medical Science. 2010. https://doi.org/10.3346/jkms.2010.25.3.492
  20. 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 Journal of Gastroenterology. 2014. https://doi.org/10.4166/kjg.2014.64.1.54

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