The bottom line
Human evidence for Giloy alone rests on a handful of small, mostly single-centre Indian trials (allergic rhinitis, HIV, diabetic foot ulcers, hyperlipidaemia, COVID-19); results are generally favourable but often open-label, underpowered or with non-significant primary outcomes[16][17][18][19][24]. Pooled COVID-19 analyses rate certainty as low to moderate, with a possible reduction in infection incidence for prophylaxis and no clear effect on hospitalisation[21][22]. Much of the wider pharmacology is preclinical[25].
RCTEvidence: limited
Allergic rhinitis
Randomised, double-blind, placebo-controlled; n=75; 8 weeks; T. cordifolia extract vs placebo (dose not stated in abstract)
Trial reported significantly greater relief of sneezing, nasal discharge, obstruction and itching with the extract than placebo, with matching changes in nasal smear cytology; extract was well tolerated.[16]
Limitations: Single small centre; extract dose/standardisation not given in abstract; not independently replicated.
RCTEvidence: preliminary
HIV (adjunct, symptoms)
Randomised, double-blind, placebo-controlled; n=68 HIV-positive adults; 6 months; T. cordifolia extract vs placebo
60% on extract vs 20% on placebo reported fewer disease-related symptoms; eosinophil count and haemoglobin fell significantly. Authors note not all objective parameters supported the symptom benefit.[17]
Limitations: Small; mixed objective results; anorexia, nausea, vomiting and weakness were reported on the extract.
RCTEvidence: preliminary
Diabetic foot ulcer healing (adjunct to surgery)
Prospective double-blind randomised controlled; n=50 (45 completed); T. cordifolia adjuvant vs control alongside standard surgical care
Net improvement 73.9% vs 59.1% (P=0.292, not significant); fewer debridements (P=0.03) and improved neutrophil phagocytosis with T. cordifolia; most wound-size measures were not statistically different.[18]
Limitations: Small; primary healing measures non-significant; single centre.
RCTEvidence: preliminary
COVID-19 treatment (mild/asymptomatic)
Open-label randomised pilot; n=30; Guduchi Ghana Vati 500 mg twice daily for 10 days vs hydroxychloroquine-based control
RT-PCR negativity by day 10 was 93.3% vs 66.6%, a difference that was not statistically significant (P=0.068); no adverse reactions observed.[19]
Limitations: Very small, open-label, active comparator now considered ineffective; conducted by Ministry of Ayush research council.
RCTEvidence: preliminary
COVID-19 treatment (mild)
Randomised open-label three-arm; n=150 (136 completed); 14 days; Adhatoda vasica 500 mg vs T. cordifolia 500 mg vs combination 250 mg each
Mean viral clearance 13.44 days on T. cordifolia alone vs 11.86 days on the combination; hs-CRP fell at mid-treatment in the T. cordifolia arm; no adverse effects reported.[20]
Limitations: No placebo or standard-care-only arm; open label; cannot isolate an effect of T. cordifolia versus natural recovery.
meta-analysisEvidence: limited
COVID-19 treatment (pooled)
Living systematic review/meta-analysis of RCTs and observational studies to Aug 2021 (17 studies; Guduchi pooled as add-on to standard care)
Add-on Guduchi 'may reduce' hospital stay (mean difference 3.93 days lower), but the 95% CI (8.83 lower to 0.97 higher) crosses no effect; appeared safe as an adjunct.[22]
Limitations: Few small studies; certainty moderate to low due to risk of bias and imprecision; authors are from an Ayush institute.
meta-analysisEvidence: limited
COVID-19 prophylaxis (pooled)
Living systematic review/meta-analysis (second update), searches to 1 March 2023; GRADE
Guduchi 'may reduce' incidence of COVID-19 infection (RR 0.67, 95% CI 0.48-0.95); no clear effect on symptom development (RR 0.88, 0.73-1.08) or hospital admission (RR 0.96, 0.20-4.53).[21]
Limitations: Certainty low to moderate, mainly serious risk of bias; few studies.
observationalEvidence: limited
COVID-19 and other infections, prevention in healthy adults
Open-label, randomised comparative community study in 5 Rajasthan districts; 10,022 completers; Guduchi Ghana Vati for 45 days vs no intervention
COVID-19 incidence was lower with Guduchi Ghana Vati but not statistically significant; severity (WHO ordinal scale) and non-COVID illness episodes were reported significantly lower; no major adverse reactions.[23]
Limitations: No placebo, open label, self-reported outcomes; authors declared financial relationships.
RCTEvidence: preliminary
Hypertriglyceridaemia
Pilot; n=24 randomised to T. cordifolia extract 3 g/day vs metformin; 14 days
Triglyceride, LDL and VLDL fell and HDL rose significantly within the extract group, with reductions in an oxidative stress marker.[24]
Limitations: Very small, very short, active comparator, within-group analyses; pilot only.
These studies explain possible mechanisms. They do not show the same effect in people.