Aloe vera plant is a spiky succulent that has been used for centuries for its skincare and medicinal properties.
The word ‘aloe’ means a shining bitter substance in Arabic, and ‘vera’ means true in Latin.
The health benefits of aloe vera juice are mainly due to the polysaccharides and vitamins found in the inner gel of the plant.  
Key Health Benefits of Aloe Vera Juice
The key benefits of aloe vera juice include reducing the symptoms of irritable bowel syndrome and treating digestive problems. It may lower periodontal indices, modulate the immune system, and reduce fasting glucose levels in diabetic patients. Few studies showed that it might reduce symptoms of GERD, improve Lichen planus, and exhibit anticancer properties.
1. Aloe vera juice reduced symptoms of irritable bowel syndrome
Studies showed that aloe vera juice reduced the symptoms of irritable bowel syndrome (IBS). It might treat digestive problems by acting as a laxative. 
In a study, aloe vera juice at a concentration of 5% promoted the growth of Lactobacillus.
Mild to moderate ulcerative colitis (type of IBS) patients who drank 200ml of aloe vera juice showed clinical improvement. 
An Iranian study showed that 30 ml of Aloe vera juice administered reduced pain, discomfort, and flatulence in IBS patients.
What it means: Aloe vera juice enhanced the growth of Lactobacillus and, therefore, may treat digestive problems. The use of aloe vera juice improved symptoms of irritable bowel syndrome, including discomfort, pain, flatulence, and acted as a laxative. Future extensive controlled studies are needed to confirm the efficacy of aloe vera juice in treating IBS.
2. Aloe vera juice may reduce periodontal indices
Studies have shown that aloe vera juice may reduce periodontal indices. It may reduce dental plaque and gingival inflammation by acting against a range of cariogenic and periodontopathic bacteria.   
In a randomized controlled trial involving 300 healthy subjects, aloe vera mouthwash reduced plaque. It was as effective as chlorhexidine.
In another study, aloe vera mouth rinses reduced gingival bleeding and plaque indices after 30 days.
A study involving 45 plaque-induced gingivitis patients, rinsing with 10ml aloe vera mouth wash daily reduced gingival inflammation.
What it means: Aloe vera juice containing mouth wash may reduce gingival inflammation and plaque by acting against oral bacteria. It was useful as chlorhexidine. Additional research studies will determine the mechanism of action and effectiveness of different aloe vera juice formulations in treating dental plaques.
3. Aloe vera juice may modulate the immune system
Research studies suggested that aloe vera juice has polysaccharides that may modulate the immune system.
Aloeride, an immunostimulatory polysaccharide extracted from aloe vera juice activated macrophages. 
Another polysaccharide, acemannan, stimulated macrophage, cytokine production, and nitric oxide release. 
In another study involving 15 healthy volunteers, a combination of vitamin C (1g/day) and aloe vera juice (50ml) increased cytotoxicity of natural killer cells.
Oral administration of aloe gel enhanced cellular, humoral immunity, and anti-SRBC antibody production in mice.
What it means: Aloe vera is rich in polysaccharides that may have immune-modulating properties. A combination of vitamin C and aloe vera juice may enhance natural killer cell activity. More studies are required to explore the molecular mechanisms of immune-modulating properties of aloe vera juice.
4. Aloe vera juice may reduce fasting blood glucose levels in prediabetes and early diabetes patients
Aloe vera juice may reduce fasting blood sugar levels in prediabetes and untreated early diabetes patients. 
A systematic review involving 415 prediabetes and early non-treated diabetic patients who ingested aloe vera juice, and other preparations showed reduced levels of fasting blood glucose levels and HbA1c.
It also modulated serum lipid markers.
Oral administration of aloe vera juice twice a day reduced blood sugar levels and triglyceride levels in diabetic patients after two weeks.
What it means: Consumption of aloe vera juice may reduce serum fasting glucose levels in prediabetic and early diabetic patients. The study did not establish the safety of consuming aloe vera juice. Future well-designed studies will determine if aloe vera juice can help in managing diabetes.
5. Aloe vera juice may reduce symptoms of gastroesophageal reflux disease
A preliminary investigation suggested that aloe vera juice may reduce the symptoms of gastroesophageal reflux disease (GERD) without any adverse effects.
GERD is a common digestive problem causing acid regurgitation and heartburn.
In a pilot, randomized controlled study, subjects who received Aloe vera syrup showed reduced frequencies of GERD symptoms.
It improved heartburn, food regurgitation, flatulence, belching, nausea, vomiting, and acid regurgitation. It was well tolerated while providing GI support. 
What it means: Recent research reported the use of aloe vera juice might reduce the symptoms of GERD through its anti-inflammatory properties. The initial research looks promising, but future research studies will determine the efficacy of aloe vera juice in treating GERD.
6. Aloe vera juice may exhibit anticancer properties
Some studies showed that aloe vera juice might exhibit anticancer properties.
In a study, 240 patients with solid metastatic tumors who received aloe vera juice (10ml thrice/day) with chemotherapy showed increased the percentage of tumor regression and survival time.
Acemannan found in aloe vera juice exhibited antitumor activities in vivo studies.
What it means: One study showed that aloe vera juice might increase the regression of tumors when used with chemotherapeutic drugs. Aloe vera had compounds that exhibited anticancer properties. Additional research studies are required to check if aloe vera juice may be used as an adjunct with anticancer drugs.
7. Aloe vera juice may play a role in treating Lichen planus
Aloe vera juice may reduce the symptoms of Lichen planus. Lichen planus is a skin disease characterized by eruptions.
A study showed that the use of aloe vera juice and gel improved symptoms of Lichen planus in a 38-year-old male patient.
It reduced intraoral and skin lesions.
Aloe vera gel application also decreased the burning pain and symptoms of Lichen planus patients.
What it means: A case study showed that aloe vera juice might reduce symptoms of Lichen planus. More randomized controlled trials will determine if aloe vera juice can be used to treat Lichen planus patients.
Precautions While Taking Aloe Vera Juice
Possible Side effects of Aloe Vera Juice
Aloe vera juice may cause diarrhea and cramping as it contains latex. Avoid taking aloe vera before a colonoscopy as it might stain the colon.
As there is no reliable information about the safety of aloe vera juice in children, pregnant and women, it is advised to stay on the safer side and avoid taking aloe vera. Avoid taking aloe vera orally if having heart disease, hemorrhoids, kidney problems, diabetes, or electrolyte imbalances.
Possible Drug Interactions
Aloe vera might interact and block the absorption of diabetes drugs, laxatives, steroids, warfarin, and diuretic drugs.
It is advised to consult a doctor before taking aloe vera juice if having these conditions. 
Dosage of Aloe Vera Juice
There is no recommended dosage of aloe vera juice available. Pure aloe vera juice, about 30 ml twice a day, maybe used for oral submucous fibrosis. 
Aloe vera juice has multiple features and great medicinal value similar to the aloe vera gel.
Small studies have suggested its role in easing symptoms of IBS, improving oral health, and modulating blood glucose levels.
Future detailed studies are required to examine its therapeutic potential, reliability, and mechanism of action in treating different pathological conditions.
Always consult a healthcare professional and use a purified aloe vera juice to avoid potential risks.