Hippocrates once said "let food be your medicine and medicine be your food". From my viewpoint this would certainly be borne out by the idea that herbal medicine blends into nutrition and dietetics at one end. When we eat, we are generally taking in megadoses of plants unless we happen not to have a vegan diet, and even then most of the species we eat are likely to be plants.
I often hear vegans say that it's our duty to try to avoid getting ill in case we then end up taking drugs produced using vivisection, although in fact it seems a bit odd to think about the idea of a duty not to become ill, partly because we presumably don't want to get ill anyway. However, what often seems to be ignored is that there is a perfectly tenable way of dealing with a whole variety of health problems which don't involve going anywhere near the pharmaceutical industry even if you do in fact become unwell, namely herbal medicine.
In the early '90s, I was of course vegan but also looking for a career I could justify on ethical grounds. After a fairly peremptory quest, I realised that the global ethical boycott approach led to certain things recommending themselves. Suppose you don't want to use the products of a particular company. On the whole this is quite straightforward. You simply don't buy anything manufactured by, say, Nestle, Unilever, Proctor & Gamble and the like. Problem solved. However, in certain circumstances you lack control over the source. This might happen if you were in school or prison for example: if you want to eat, you end up having little choice but to eat stuff made by Nestle or something, and you lack the option to lobby or petition to get this changed.
The same situation exists in medicine. If you go to a GP and are prescribed drugs, the chances are those drugs will be made by a highly unethical undertaking which includes animal products in them, has researched them on animals, and therefore may have ended up with inappropriate medication which either doesn't work as well as it would if it had been researched properly or works but has various undocumented side effects, and may even be producing them directly from animals. If, on the other hand, you take herbal remedies, you are taking vegan substances whose action is usually established via the communal research of millenia of tradition, may or may not have been tested on animals but you needn't have any economic connection with that when you use them, and absolutely will not be from an animal, because it's a herb.
By the way, to state the obvious, it does work and I can't be bothered to argue with someone who refuses to see this. We all know it works unless we're blinded by prejudice or don't know what we're talking about, so please don't be silly and claim it doesn't.
Of course, it doesn't always work because we don't live in a perfect world. When lifestyle factors have been taken into consideration and someone doesn't appear to be doing anything which will provoke or exacerbate their condition, maybe herbs won't help them. Sometimes herbs aren't even appropriate. When these things happen, clearly we might need to think about using pure compounds instead, and that's fine. However, it very often doesn't, and when it doesn't it makes sense to use herbs. I really wish people would remember the option was there.
Even if it didn't work, there would still be at least two arguments for using them. Many problems go away on their own without treatment, and if a person can tide themselves over that time without resorting to substances emerging from a long story of cruelty to animals, why not do so? Also, if it doesn't work directly, there's still the placebo effect and that can get you through as well.
Therefore the choices are not between not getting ill and using non-vegan medicine. The choices are between not getting ill, using vegan medicine, i.e. herbal remedies, and using non-vegan medicine. It would be good if people recognised this.