FIRST AMENDMENT TO AMENDED AND RESTATED NOTE PURCHASE AGREEMENT

Exhibit 10.1

FIRST AMENDMENT

TO

AMENDED AND RESTATED NOTE PURCHASE AGREEMENT

THIS FIRST AMENDMENT TO AMENDED AND RESTATED NOTE PURCHASE AGREEMENT (the “Amendment”), dated and effective as of August 10, 2009, by and between INTERLEUKIN GENETICS, INC., a Delaware corporation (the “Company”), and PYXIS INNOVATIONS INC., a Delaware corporation (“Pyxis”).

WHEREAS, the Company and Pyxis are parties to an Amended and Restated Note Purchase Agreement dated as of March 10, 2009 (the “Agreement”), pursuant to which Pyxis extended the Company a credit facility (the “Credit Facility”) in an amount (following applicable adjustments) not to exceed Fourteen Million Three Hundred Sixteen Thousand Two Hundred Fifty-Five Dollars and No/100 ($14,316,255.00) on which the parties may draw down until March 31, 2010 (the “Credit Facility Termination Date”);

WHEREAS, Pyxis purchased, and the Company sold and issued to Pyxis, (i) a pr