2006
抽脂虽然是一个很有效的方法，但许多人并不想手术。这些爱美人士希望能打个针抹个药就能消除脂肪。近年市场出现了一种号称消脂针的药 —Phosphatidylcholine (磷脂胆碱)，只要在想瘦部位打针，就能除去局部脂肪推积。
我们来看看这个以兔子为对象的实验:
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.
首先我们来看作者。我注意到 PG Rittes 连续在医学杂志发表了二篇关于消脂针除眼袋及局部脂肪堆积的文章。本文则是他的第三篇文章，是用兔子来做实验。你是否发现什么事不对劲呢？ 
顺道一提， Rittes 是巴西人，这个遥远的国度可说是中南美洲美容手术最盛行的地方，很多希奇古怪的方法都是巴西人先”尝试”的。
其次，关于文章的结果是很简单的：把消脂针注入兔子体内，几天后解剖，然后可见脂肪细胞溶解，証实了这针的确有用。
三年前台湾有许多医师在看过 Rittes 前二篇的论文后，马上开始帮人打消脂针除眼袋，尤其是一些美塑疗法(methotherapy)的业者更是积极，马上引入很多种商品供注射。我只想提醒大家一下：Rittes 之后的论文有人提到消脂针之所以有作用可能不是磷脂胆碱的关系，而是它所用的溶剂。而国内厂商进口了一大堆产品，那种才是真正有效？那种才安全？这似乎没有人在把关。
2009
有些医师继续针对消脂针的问题做研究，得到新的结论如下:
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.
这篇文章是德国人写的，果然德国人做学问比较严谨些。他们把消脂针的主成份 phosphatidylcholine 和界面活性剂 deoxycholate分别加入含脂肪细胞的培养皿中，然后测脂肪细胞的活性和脂肪被脂解后的产物glycerol. 结果发现脂肪细胞的确会死掉，但是脂肪颗粒并未被分解，脂肪细胞死亡的原因是界面活性剂 deoxycholate的关系，Phosphatidylcholine在整个过程中毫无作用。
问题来了，一旦所谓的消脂针并不是只针对脂肪细胞而作用，而是会破坏所有细胞(deoxycholate会破坏细胞膜)，那么注射消脂针会不会伤害神经或血管呢? 答案应该是很明显了。
2015
FDA核准一款消脂针 Belkyra (倍克脂)用于改善双下巴。2017年4月台湾卫生署也核准这款药在台销售。
大家知道Belkyra的成份是什么吗？phosphatidylcholine ? ❌， 答案是deoxycholate !
那之前说deoxycholate可能会伤到神经，Belkyra就不会吗？❌，答案是会！不过厂商调整过浓度，只会暂时伤害，几个月后神经功能会恢复。
