efficacious

Successful in producing a desired or intended result; effective.

• efficacy/ˈɛfɪkəsi/(n)效力
• efficaciously/ˌɛfɪˈkeɪʃəsli/(adv)有效地

• efficacious treatment
• efficacious remedy
• prove efficacious
• clinical efficacy

1. 1.The vaccine proved highly efficacious in clinical trials. (effective)
2. 2.Is there an efficacious remedy for this condition? (that actually works)

• effective/ɪˈfɛktɪv/— achieving results, general
• potent/ˈpəʊtənt/— powerful in effect
• productive/prəˈdʌktɪv/— yielding results

from Latin "efficax" = powerful — "efficere" = to accomplish