That's a good question. There are several ME/CFS treatments which can help, and can sometimes make major improvements; but the trouble is that treatments which one ME/CFS patient finds beneficial may not work for the next patient, and there's not much indication in advance of which treatments might work for a given patient.
So for the most part, it's a case of trial and error, testing out various treatments to see if they work for you. Some treatments just involve supplements which you can buy online, whereas other involve prescription drugs.
Here in the UK, usually GP doctors are very reluctant to prescribe prescription drugs on an experimental basis for ME/CFS patients. So unfortunately that rules out drug treatments, unless you go to an internationally-reknowned ME/CFS doctor like Dr Kenny De Meirleir in Brussels, who will prescribe drugs.
You can of course bypass your GP and buy drugs from
prescription-free pharmacies, and that's fine if you are taking the drugs yourself; but it's not really a good idea to buy prescription drugs for someone else.
So let's look at the supplements that you might consider trying:
Some ME/CFS patients find high dose
vitamin B12 injections useful for reducing brain fog and fatigue. Injectable B12 is a prescription item, but fortunately there is a
freely-available transdermal B12 formulation which is just as good if not better than injections.
ME/CFS is usually linked to either
herpesviruses (like Epstein-Barr virus, cytomegalovirus or HHV-6), or else
enteroviruses (like coxsackievirus B and echovirus). Taking the right viral blood tests can determine which viruses are involved, but this is tricky, because for enterovirus, we do not have the right tests in the UK, so a blood serum sample must be sent abroad to testing labs. Though sometimes the symptoms of the initial acute infection which triggered the ME/CFS can give some clues as to which virus it is.
If you daughter does have ME/CFS linked to active coxsackievirus B infection, then the herbal supplement
oxymatrine has shown benefit for these patients. You can even try oxymatrine without viral testing. My
roadmap gives more detail, if you search for the word "oxymatrine".
If your daughter has intestinal issues like
small intestine bacterial overgrowth (SIBO), then herbal treatment of SIBO can result in great gains in energy. SIBO is normally tested for by a breath test, available privately in the UK, but hard to find on the NHS. See the SIBO section in the
roadmap.
Supplements which have potent antidepressant effects comparable to drugs include
Spanish saffron 100 mg twice daily (be careful to avoid
fake saffron). Ref:
1
You can test your daughter for POTS very easily at home (see POTS section of
roadmap). If she has POTS, then simple treatments like giving salt can help.