Tetrandrine a bis-benzylisoquinoline alkaloid, is a calcium channel blocker. It has anti-inflammatory, immunologic and antiallergenic effects. It inhibits the degranulation of mast cells. It has a "Quinidine like" anti-arrhythmic effect. It has been isolated from Stephania tetrandra S Moore, and other Chinese and Japanese herbs. 

It has vasodilatory properties and can therefore reduce blood pressure.

Tetrandrine may have potential use for the treatment of liver disease and liver cancer.

Tetrandrine has potential therapeutic value to prevent excess scarring/fibrosis in conjunctiva following trabeculectomy or in patients with severe conjunctival inflammation.

Tetrandrine has anti-inflammatory and anti-fibrogenic actions, which make tetrandrine and related compounds potentially useful in the treatment of lung silicosis, liver cirrhosis, and rheumatoid arthritis.

Tetrandrine has also been shown to inhibit entry of Ebola virus into host cells in vitro and showed therapeutic efficacy against Ebola in preliminary studies on mice.
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Tetrandrine allowed occurrence of the neuroprotective effect of [[glutathione]] probably due to inhibition of [[P glycoprotein]] on 6-hydroxydopamine-lesioned rat models of Parkinson's disease, including rats undergoing long-term L-dopa treatment
((Li XY, Mei GH, Dong Q, Zhang Y, Guo ZL, Su JJ, Tang YP, Jin XH, Zhou HG, Huang
YY. Enhanced Neuroprotective Effects of Coadministration of Tetrandrine with
Glutathione in Preclinical Model of Parkinson's Disease. Parkinsons Dis.
2015;2015:931058. Epub 2015 Nov 18. PubMed PMID: 26664824.)).