Does Korean red ginseng help against fatigue?
For fatigue caused by illness or cancer therapy there are indications that ginseng makes a modest difference; for everyday fatigue the evidence is thinner. If you have an illness or are taking medication, it is wise to discuss this with your doctor.
Korean red ginseng (3,000 mg per day for 12 weeks) reduced symptoms of cancer-related fatigue in studies in people, with a good safety profile and only mild side effects. A larger study in colorectal cancer patients receiving chemotherapy (2,000 mg per day for 16 weeks) showed clear improvements in mood, walking ability, and enjoyment of life. A shortage of white blood cells occurred slightly more often in the ginseng group, but the total number of side effects was comparable to placebo. If you are considering ginseng as a supplement alongside cancer treatment, discuss this with your doctor first.
In people with chronic fatigue without an underlying illness, the picture is less clear. In a small study of 50 people, Korean red ginseng (3 grams per day for 6 weeks) did not reduce fatigue any better than a placebo. Only in people over 50 with moderate fatigue was there a clear benefit. That is a finding from one small group within a small study, so it should not be given too much weight.
More research is available on ginseng more broadly, meaning not just the Korean red variety. Across 12 studies involving 1,298 people with illness-related fatigue, a small but real effect was found. In cancer patients, seven studies combined also showed a small real effect on fatigue, along with improvements in physical and emotional wellbeing. For healthy people without an underlying condition, ginseng does not improve physical performance.
In practical terms: if you experience fatigue due to a chronic condition or during cancer therapy, there are indications that ginseng may help to some degree, although the effect is modest. For ordinary everyday fatigue, the evidence is thinner. Bear in mind that the quality of studies varies considerably and that most effects are small.
This answer draws on several combined analyses of studies and some individual studies in people. The strongest finding comes from a large, well-controlled study in colorectal cancer patients. The remaining findings come from summaries of 7 to 12 studies in people, or from smaller individual studies. The researchers rate the quality of the evidence for most outcomes as mixed. For general fatigue in healthy people, the combined results just fall short of showing a clear effect. The researchers behind the study in athletic or healthy people concluded themselves that the evidence is insufficient due to the small number and small size of the studies.
Does red light therapy really have an effect on your cells?
Red light therapy has a biologically plausible effect on cells, with positive clinical indications for pain and recovery, but standard doses are lacking and home devices have not been sufficiently studied. Interest is justified, but keep your expectations realistic until more standardised research is available.
Does echinacea really work against the common cold?
Whether echinacea helps with the common cold depends strongly on which preparation you use. Standardised products made from Echinacea purpurea (herb and root) showed a modest reduction in symptoms in some studies, but root extracts and non-standardised products did not improve outcomes, and what you buy in a shop rarely corresponds to the products used in positive studies.
Does extra salt help with fatigue during fasting?
Baking soda (sodium bicarbonate) reduced fatigue in trained men who had fasted and then exercised, but this was found in only one small study and says nothing about everyday fasting-related fatigue. Ordinary table salt has not been studied for this purpose.
Does quercetin work against ageing and inflammation?
Quercetin shows promising signals in the laboratory and in animals, but in humans there is not yet solid evidence. Taking supplements on the basis of this early-stage research gets too far ahead of the science.
Does ashwagandha really work against stress?
Ashwagandha demonstrably lowers the stress hormone cortisol, but whether it also makes you actually feel less stressed has not been convincingly proven in independent research. Short-term use of up to around 12 weeks appears safe, but too little is known about long-term use to be certain.
Does taking resveratrol make sense as an anti-ageing strategy?
For humans there is no convincing evidence that resveratrol supplements do anything against ageing; the animal research is interesting but has not yet translated into clinical practice, so hold off on supplements until better human data are available.