我猜想应该complimentary”在这里应该是诸如“值得一提的”、“很有用的”等的意思。
“Herbal Treatments – A Complimentary Aid to Alzheimer’s Patients
”意思大概是“草药治疗 - 对阿尔茨海默氏症患者疗效显著的一种治疗方式”
“Topical nail fungus medications are recommended as a complimentary aid to oral treatment. ”意思可能是“局部指甲真菌药物作为一种有效的药物推荐给患者，通过口服治疗。”


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Note added at 8 hrs (2011-09-07 21:45:50 GMT)
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前面提供的连接有误，下面是我参考的内容
Topical nail fungus medications are recommended as a complimentary aid to oral treatment. They can help when directed appropriately. These creams are applied directly on the nail. By itself. a cream has little power and in most cases will not be enought to cure the infection.

Topical creams use special chemicals and ingredients that help pass through the nail and reach the fungus.

Please do remember that these medications have side effects and are not effective on anyone. Thus, you must not take any medicine without consulting with your physician first.

http://nailfungusremedies.net/Nail_Fungus_Medications.html

首先同意"complementary aid"可能性大一些，根据我的从业经验，中药最多对西医来说只能是一种在西医药物治疗基础上的补充治疗或者说辅助治疗，谈不上首选治疗。
但是因为提供的上下文较少，如果比如说是草药治疗的推广宣传，将其说成是“值得推荐”或者“值得赞赏的”治疗也未尝不可。
希望能提供更多的上下文联系