The evidence for homeopathy comes from two main sources – the studies and trials undertaken, and the experience of the many people who use it. My impression is that many people don’t realise that these studies and trials exist as they often don’t appear in the mainstream media.

The individualised approach of homeopathy does not always lend itself well to clinical trial structures, and the resources needed for large-scale trials are mostly beyond the research and financial resources of those outside of the pharmaceutical industry. However, there are studies and trials that you can refer to. Some focus on patient experiences and outcomes of homeopathy, such as the Bristol Homeopathic Hospital Clinical Outcome Study, 1997-99:
“An observational study at Bristol Homeopathic Hospital included over 6,500 consecutive patients with over 23,000 attendances in a 6-year period[6]. Seventy percent of follow-up patients reported improved health, 50% referring to major improvement. The best treatment responses were reported in childhood eczema and asthma, and in inflammatory bowel disease, irritable bowel syndrome, menopausal problems and migraine in adults. Similar patient-reported outcomes have been reported from the UK’s other four NHS homeopathic hospitals[7-10].” Source: Faculty of Homeopathy website, please see link and references below.

There are also a number of randomised controlled trials looking at the effectiveness of homeopathy in various conditions. If you visit the Find A Homeopath website it can give you more details around these, and further links if you would like more information
http://www.findahomeopath.org/WhatIsHomeopathy/Evidence

The website for the Faculty of Homeopathy (involved with the education, training and practice of homeopathy by the medical profession) also offers information about trials and a download summary with full references http://www.facultyofhomeopathy.org/research/

In Switzerland the Health Technology Assessment report was “compiled on behalf of the Swiss Federal Office for Public Health presented the findings of a seven-year review of the evidence on homeopathy. It concluded that homeopathy, as practiced in Switzerland, is clinically effective, cost-effective and safe. Homeopathy has since become available to the Swiss public as part of their national healthcare scheme.” (2011) Source: Homeopathy Research Institute https://www.hri-research.org/resources/homeopathy-the-debate/

Given how individually-tailored homeopathic treatment is, it can also be very interesting to look at testimonials from people who have used it, what it has helped them with and their positive experiences http://www.findahomeopath.org/Testimonials

There are also organisations where you can look up recent pieces of research and reviews such as the Homeopathy Research Institute and the recent research which detected physico-chemical difference between homeopathic preparations and water. http://dx.doi.org/10.1016/j.homp.2015.08.002

This is a system of medicine that has been practiced for over 200 years, across the world, used by millions of people – there is a wealth of information to share about it and many, as you will see from the testimonials trust the truth of their own experience.

References
Clinical Outcome Study, Bristol Homeopathic Hospital, 1997-99 http://www.facultyofhomeopathy.org/research/

[6] Spence DS, Thompson EA, Barron SJ. Homeopathic treatment for chronic disease: a 6-year university-hospital outpatient observational study. Journal of Alternative and Complementary Medicine, 2005; 5: 793–798.
[7] Clover A. Patient benefit survey: Tunbridge Wells Homoeopathic Hospital. British Homeopathic Journal, 2000; 89: 68–72.
[8] Richardson WR. Patient benefit survey: Liverpool Regional Department of Homoeopathic Medicine. British Homeopathic Journal, 2001; 90: 158–162.
[9] Sharples F, van Haselen R, Fisher P. NHS patients’ perspective on complementary medicine. Complementary Therapies in Medicine, 2003; 11: 243–248.
[10] Reilly D, Mercer SW, Bikker AP, Harrison T. Outcome related to impact on daily living: preliminary validation of the ORIDL instrument. BMC Health Services Research, 2007; 7: 139.