I just bought Lecithin capsules, because I read that they help promote weight loss...Is it true?

As with any weight loss product, BE CAREFUL!
Lecithin is important for the body's utilisation of fat and cholesterol and is important for a healthy cardiovascular system. Healtheries Lecithin is derived from soy.
It is recommended for "USE AS PART OF A WEIGHT LOSS PROGRAM....."
not as a stand alone weight loss thing.....
so, without diet and exercise....NOTHING will take off the weight....
most just make you feel FULL....
again, be careful..as some tend to cause heart palpitations etc.....research it FIRST!
and good luck.