最近正好在查询小檗碱的文献，顺便看了下知乎上有关小檗碱的回答。我想问一下，大家吃的小檗碱片苦不苦？--我是被苦了好久。
言归正传，你想看临床数据，只看pubmed还不够吧，我来从其他角度试着告诉你可能的答案，自己判断：
可以在
（临床上注册的药物试验都可以找到）中搜索下小檗碱嘛，berberine，随手打开一下小檗碱的临床试验，确实很多的。先看这个
The primary efficacy outcomes were changes in plasma glucose and serum lipid levels
血糖和血脂都可以改变的。
After 3 months, fasting and post load plasma glucose levels, HbA1C, triglyceride, total cholesterol and LDL-C levels were all significantly reduced in the berberine group compared with the placebo group (p<0.0001, p<0.0001, p<0.0001, p=0.002, p<0.0001 and p<0.0001 respectively). Our results show berberine to be effective and safe in the treatment of persons with diabetes and dislipidemia. This agent may be useful in the treatment of patients with type 2 diabetes, and could play a role in treatment of metabolic syndrome.三月之后，各项指标都很好。
简单来说，看来小檗碱对于二型糖尿病还是很有效的，也没发生什么不良反应。这可是随机对照的双盲试验。
再看这篇 Ni Y, Liu A, Gao Y, et al. Therapeutic effect of berberine on 60 patients with non-insulin dependent diabetes mellitus and experimental research[J]. Chinese Journal of Integrated Traditional and Western Medicine, 1995, 1(2): 91-95. 疗效妥妥的，自身对照的实验。
至于楼上说溶解度低，不见得，logP=-1.5[1],肯定是水溶性的化合物，这篇提高它溶解度的文章中，测得其溶解度最小值为5.27mmol，它的分子量是371.8，也就是1.96mg/ml，按照药典规定的方法来计算的话，日常剂量100-300 mg，溶解度根本不存在任何问题。
我反倒认为可能是渗透性影响它的吸收[2]
[1] Battu S K, Repka M A, Maddineni S, et al. Physicochemical characterization of berberine chloride: a perspective in the development of a solution dosage form for oral delivery[J]. Aaps Pharmscitech, 2010, 11(3): 1466-1475.
[2]Baird A W, Taylor C T, Brayden D J. Non-antibiotic anti-diarrhoeal drugs: factors affecting oral bioavailability of berberine and loperamide in intestinal tissue[J]. Advanced drug delivery reviews, 1997, 23(1): 111-120.
