本文首先架構起一個搖頭丸在台灣的存演脈絡圖像，分析從西方進入台灣的「快樂丸」如何逐漸在地化以「搖頭丸」之名廣為流通。我們指出在這個在地化過程中，國家機器的毒品防治策略如何介入其中，並質疑國家機器對於搖頭丸的防治有效性與爭議。 在訪談的過程中，我們發現國家機器在制度面所公開形構的搖頭丸，與制度代理人（員警、戒治所人員）的實作經驗中存有矛盾。我們試圖理解這種矛盾的發生原由，同時也藉此質疑這個毒品分類的有效性。當我們尋求國家機器對於這樣一個曖昧的毒品分類其立論基礎何在，然而卻發現應該具備的在地資訊竟是相當缺乏的。國家機器所援引的醫學證據或毒品分類僅僅只是「選擇」某個「先進國家」。最後，我們轉向理解用藥者如何對自我用藥行為（涉及違法部份）的詮釋。然而在面對一個已制度化的意識形態，他們無意挑戰這個可疑的分類，甚至根本上忽視自主意識的存在必要。

This article attempts to first sketch out an evolving contextual picture of “head wriggling pills” in Taiwan, and hence, to analyze how its West originated expression, the “happy pills” so to speak, has been localized to be named as “head wriggling pills”. We also try to expose the state intervention in the localization process through the drug-prevention policy of the ideological state apparatuses, and to question the efficacy of the state apparatuses’ deterrence of “head wriggling pills”. During the interviewing process, we found out that the officially formulated discourse of “head wriggling pills” by the state apparatuses contradict the practical experience of their institutional agents (such as police officers and practitioners at the Drug Abstention and Treatment Center). We try to figure out the cause of this contradiction and thereby to challenge the effectiveness of the current classificatory framework of drugs. As soon as we attempt to seek out the theoretical foundation of state’s ambiguous drug categorization, we realize that the necessary local information concerning the categorization is extremely insufficient. Actually, the medical evidence and drug categorization of the state relies selectively on specific “advanced country”. Finally, we shift to comprehend the drug-users’ self-interpretation of their drug-using behavior, especially the “illegal parts”. We find out that under the already institutionalized ideology, drug-users have no intent to challenge the dubious categorization, and thereby they ignore the necessity of their own autonomous consciousness.