2006
抽脂雖然是一個很有效的方法，但許多人並不想手術。這些愛美人士希望能打個針抹個藥就能消除脂肪。近年市場出現了一種號稱消脂針的藥 —Phosphatidylcholine (磷脂膽鹼)，只要在想瘦部位打針，就能除去局部脂肪推積。
我們來看看這個以兔子為對象的實驗:
Authors Rittes PG. Rittes JC. Carriel Amary MF.
Institution Santa Casa School of Medicine, Rua Afonso Braz, 864, cj. 72, Vila Nova Conceicao, Sao Paulo, SP, Brazil.
Title Injection of phosphatidylcholine in fat tissue: experimental study of local action in rabbits.
Source Aesthetic Plastic Surgery. 30(4):474-8, 2006 Jul-Aug.
Abstract
BACKGROUNDS: Subcutaneous phosphatidylcholine to cause local lipolysis has been performed effectively and safely in the nonsurgical treatment of periorbital fat pads and also in the treatment of localized fat deposits in the abdomen, neck, arms and thighs. However, the studies do not explain the mechanism through which injectable phosphatidylcholine causes localized fat reduction. This study aimed to compare the local action of a phosphatidylcholine formulation with that of a physiologic saline solution in a histologic study investigating the fat tissue of rabbits. METHODS: Using a randomized, blind approach, 10 rabbits were injected with an experimental assay of phosphatidylcholine (the biologic model), and another 10 rabbits were injected with physiologic saline. A histologic study was conducted, and the Mann-Whitney test was applied. RESULTS: A marked difference was observed between the two groups with respect to necrosis, inflammatory exudation, and fibrosis. CONCLUSION: Necrosis of the fat cells in all the phosphatidylcholine-injected animals was observed. Further studies should be performed to clarify and determine the mechanisms of action.
首先我們來看作者。我注意到 PG Rittes 連續在醫學雜誌發表了二篇關於消脂針除眼袋及局部脂肪堆積的文章。本文則是他的第三篇文章，是用兔子來做實驗。你是否發現什麼事不對勁呢？ 
順道一提， Rittes 是巴西人，這個遙遠的國度可說是中南美洲美容手術最盛行的地方，很多希奇古怪的方法都是巴西人先”嘗試”的。
其次，關於文章的結果是很簡單的：把消脂針注入兔子体內，幾天後解剖，然後可見脂肪細胞溶解，証實了這針的確有用。
三年前台灣有許多醫師在看過 Rittes 前二篇的論文後，馬上開始幫人打消脂針除眼袋，尤其是一些美塑療法(methotherapy)的業者更是積極，馬上引入很多種商品供注射。我只想提醒大家一下：Rittes 之後的論文有人提到消脂針之所以有作用可能不是磷脂膽鹼的關係，而是它所用的溶劑。而國內廠商進口了一大堆產品，那種才是真正有效？那種才安全？這似乎沒有人在把關。
2009
有些醫師繼續針對消脂針的問題做研究，得到新的結論如下:
Author Klein, Silvan M.; Schreml, Stephan M.D.; Nerlich, Michael M.D., Ph.D.; Prantl, Lukas M.D., Ph.D.
Institution Regensburg, Germany
From the Department of Traumatology, Division of Plastic Surgery, and the Department of Dermatology, University Hospital of Regensburg.Title In Vitro Studies Investigating the Effect of Subcutaneous Phosphatidylcholine Injections in the 3T3-L1 Adipocyte Model: Lipolysis or Lipid Dissolution?
Source Plastic & Reconstructive Surgery. 124(2):419-427, August 2009.
Abstract
Background: The demand for lipolytic injection therapies for aesthetic indications increases continuously. The substance most frequently discussed in this context is phosphatidylcholine solubilized in sodium deoxycholate, a composition known in Europe as Lipostabil (Artesan Pharma, Luchow, Germany). The evidence for its lipolytic effect is based mainly on clinical studies that suggest a decrease in adipose tissue volume after subcutaneous injections. However, neither the actual effect nor the effective supplemental effect of Lipostabil has been clearly identified so far. The purpose of this study was to investigate the effects caused by lipolytic formulations on adipocytes using an in vitro model.Methods: 3T3-L1 adipocytes in 12-well plates were exposed to varying doses of isolated phosphatidylcholine, deoxycholate, and the combination of both (Lipostabil). Subsequently, changes in the cell membrane integrity were evaluated microscopically, and assays measuring the amount of glycerol as a biochemical lipolysis substrate (lipolysis assay) together with dimethyl thiazolyl diphenyl tetrazolium assays were performed to quantify the lipolytic effect and the cell viability.
Results: Deoxycholate reduced cell viability significantly (p < 0.05), even at low concentrations. Neither phosphatidylcholine nor deoxycholate led to a significant (p < 0.05) induction of a lipolytic pathway. Lipostabil, the combination of deoxycholate and phosphatidylcholine, led to a significant (p < 0.05) decrease in cell viability at low doses and to a highly significant (p < 0.01) reduction at high doses. The loss in cell viability is attributable to changes in the cell membrane integrity.
Conclusions: These results suggest that no enzymatic lipolytic pathway is induced. The decrease in volume after Lipostabil injections is likely attributable to the detergent effect of deoxycholate.
這篇文章是德國人寫的，果然德國人做學問比較嚴謹些。他們把消脂針的主成份 phosphatidylcholine 和界面活性劑 deoxycholate分別加入含脂肪細胞的培養皿中，然後測脂肪細胞的活性和脂肪被脂解後的產物glycerol. 結果發現脂肪細胞的確會死掉，但是脂肪顆粒並未被分解，脂肪細胞死亡的原因是界面活性劑 deoxycholate的關係，Phosphatidylcholine在整個過程中毫無作用。
問題來了，一旦所謂的消脂針並不是只針對脂肪細胞而作用，而是會破壞所有細胞(deoxycholate會破壞細胞膜)，那麼注射消脂針會不會傷害神經或血管呢? 答案應該是很明顯了。
2015
FDA核准一款消脂針 Belkyra (倍克脂)用於改善雙下巴。2017年4月台灣衛生署也核准這款藥在台銷售。
大家知道Belkyra的成份是什麼嗎？phosphatidylcholine ? ❌， 答案是deoxycholate !
那之前說deoxycholate可能會傷到神經，Belkyra就不會嗎？❌，答案是會！不過廠商調整過濃度，只會暫時傷害，幾個月後神經功能會恢復。
