Not the best of comparisons. Salicylic acid (the main active component in willow bark for pain relief) was used for awhile, but proved problematic because of serious side effects (i.e. on the gastrointestinal tract). Willow bark itself was (and is) prone to markedly inconsistent results due to problems of standardization and purity.
There are still people who think willow bark is a superior pain remedy, overlooking the fact that preparations are bound to be highly variable in content and efficacy. It’s the “natural must be safer and better” fallacy. It took the the development of acetylsalicylic acid (aspirin) for truly effective and safer pain relief to be achieved.
As for SJW, this article details some of the potential benefits and problems with its use.
“As is the case with many dietary herbal supplements, the amount of active ingredients may vary significantly depending on the source, time of the year of the harvest, plant component used, and the type of preparation. For example, one study analyzed the total naphthodianthrone content of 54 commercially available preparations of St. John’s wort. The measured amounts varied considerably from those claimed on the labels, from 0% to 109% for capsules and from 31% to 80% for tablets.[2] Another group reported that, whereas the amounts of pseudohypericin among 30 plants did not vary significantly, the concentrations of hyperforin did vary significantly. Such variability has significant implications for potential herbal-drug interactions and efficacy, as noted below…
St. John’s wort has gained considerable popularity as a dietary herbal supplement for the treatment of depression. There have been numerous trials using standardized St. John’s wort extracts. Results were variable, probably due to the heterogeneity of the presumed active components and lack of double-blind placebo-controlled trials. However, several statistically significant observations have emerged from meta-analyses of these trials. For mild-to-moderate depressive disorders, it appears that St. John’s wort may be as effective as SSRIs and more efficacious than placebos. However, it has not been found to be uniformly effective in major depressive disorders. With the exception of its effects on drug transport and metabolism, St. John’s wort appears to have relatively few side effects. Although the incidence is low, the most common side effects of St. John’s wort appear to be headache, dry mouth, nausea, gastrointestinal upset and sleepiness. A rare side effect reported for St. John’s wort is photosensitivity.
Words of Caution
Because of its availability as an herbal supplement, many individuals are taking St. John’s wort without consulting or informing their physicians or pharmacists. This is problematic because of the potential for an herbal-drug interaction. Most notably, taking St John’s wort could lead to a loss of efficacy of a prescription drug because of the induction of one or more drug metabolizing enzymes ( Table 1 ). Because of the variable content of its components, taking St. John’s wort could also lead to changes in efficacy or potential toxicity, depending on when the pharmaceutical was started and how many different preparations of St. John’s wort were consumed. Another potential concern is for those patients taking SSRIs who decide to add St. John’s wort to their therapeutic regimen. They are at increased risk of experiencing the serotonin syndrome, a potentially serious adverse event which may be manifested by symptoms of lack of coordination, hyperreflexia, agitation, coma, confusion, tremor, fever, nausea and diarrhea ( Table 2 ). Patients often believe that if a drug is “natural” then it is safe. This is simply not true, and patients must be cautioned about the potential risks if they choose to treat their depression with St. John’s wort.”