There are suppliers online who will sell it. Some Chinese acupuncturists might sell it but prices tend to be higher than purchasing online. I purchase multiple packs of 500grams at a time to keep the delivery costs down.
It might be worth trying a small amount say 200 grams or 0.5 pounds for a couple of weeks to see how you get on. It is available on Amazon and eBay but not at the best prices. I boil about 54 grams at a time which last me about 3.5 days and I boil Gou Qi Zi with it at about 35 grams. Gou Qi Zi which is a red berry appeals to me, I could eat piles of it but it is like many berries, high in carbs which does not go well with my diabetes therefore I cannot really eat them
It is meant to be the polysaccharides which stimulate the immune system and are anti ageing. Boiling them gives very little carbs.
Both of these are also available as an powder extract but I never found them very effective. That might be because of the oils that boiling extracts which might not be complexed in powder extracts. The Gou Qi Zi is more effective as a powder extract which is probably due to the polysaccharides which are easier to extract than oils.
I was referred for a synacthen adrenal test by a consultant and I was taking Tu Si Zi at the time. I did not stop it as I dislike not taking it. I left it to the night before before I stopped it and on the day of the test my adrenal result showed a massive amount of cortisol because I came off it so quickly. My adrenals were declared as being fully functional as a result which I know that they are not. They are much better than they were but still not 100% functional. This can often be seen in the iris at just inside 6 o clock as a grey marking. Some iris types such as blue/grey/green linen and silk irises show it easier than darker irises. It should be visible in darker irises but it is more difficult to see clearly. A very good light and maybe some magnification with a low powered x3 magnifying glass placed on a mirror might show it better. However not easy if you wear glasses. At just inside 6 o clock in both irises are the kidneys and above them just inside a ring at about 1/3 the way from the pupil are the adrenals. Any grey markings in this area indicate lowered adrenal function. Further down in the kidney zone does not mean any kidney disease it is the nervous system AND the brain which is affected. This can affect the mood and stress response. This is the normal adaption to stress which results in an elevated level of background cortisol.
Chinese medicine which is over 2000 years old has quite a few herbs to treat the kidney such as toning the kidney and liver. These toning herbs affect the rings which go around the iris causing them to relax, release and become wider and less deep. Healing past these rings is difficult without assistance unless the rings are released by herbs and relaxation. This is why conditions like depression are very rarely ever resolved and require constant maintenance medication which never solves the problem - it's highly profitable! Conditions like depression, anxiety and adrenal insufficiency can be resolved if they are treated correctly and the condition is reversed which takes some time.
The rings that I mentioned, which are shadowy rings which run around the iris at different places are related to the emotions and drives. Repressed emotions and drives cause these rings and are what causes ageing the skin being affected first as it is at the outside of the iris. Older people will have much deeper and tighter rings than young people and babies should not have any because they have not learnt to repress emotions by their parents. Parents are very damaging to their children by not directing children correctly! This causes a lot of unnecessary stress, depression and anxiety. Teaching a child correctly would avoid all of this but children do not come with manuals and the medical profession are amateurs and unknowledgeable in these topics.
Different emotions relate to different organs. The kidneys relate and are affected by fear/stress. The lungs sadness and the liver anger. The hearts is meant to be joy and the spleen I have forgotten. You might notice that rings run from just inside 6 o clock to other areas such as 2 o clock Left and 10 o clock Right. This can indicate the repression of sadness ie not being able to cry. The right is the outer expression ie crying and the left is the inner feeling, one or both can be repressed. When a ring runs from 10 to 6 o clock this means a fear of expressing sadness. This can in some people cause or increase constipation if the ring appears inside the colon. A ring from just inside 8 o clock Right iris to just inside 6 o clock is fear of expressing anger. Relaxing this ring through the liver does help the liver function and can affect the mood too. Fear of expressing sadness ie crying and fear of expressing anger is very common in depressives. These all eventually cause changes to the brain and nervous system which results in an increase in background cortisol levels. ie Adaption to stress.
I have looked at Chinese medicine which taught me a great deal and later iridology which shows the effects of Chinese toning herbs as the rings can be seen to become wider and less deep as they are relaxed. Iridology which if you believe the BS on the web such as confessions of an iridologist which is meant to put people off using Iridology and I will point out that if he was a legitimate Iridologist then he could not of been a very good one because the iris chart shown on the webpage is a very old and outdated (1982) chart which is not used by any serious Iridologist. It's most likely published by other interested parties whose profits are threatened by Iridology if people see the damage that conventional treatments cause to the human body and nervous system. Why would any drug company want anyone to find a cure for their depression and/or anxiety when they can profit by selling ineffective and damaging medications for a persons lifetime?