As filed with the Securities and Exchange Commission on October 10, 2001

Registration No. 333-64456
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SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
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AMENDMENT NO. 6

TO
FORM S-1
REGISTRATION STATEMENT
Under The Securities Act of 1933
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THERASENSE, INC.
(Exact name of Registrant as specified in its charter)
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Delaware 3841 94-3267373
(State or other jurisdiction of (Primary Standard Industrial (I.R.S. Employer
incorporation or organization) Classification Code Number) Identification Number)

TheraSense, Inc.
1360 South Loop Road
Alameda, California 94502
(510) 749-5400
(Address, including zip code, and telephone number, including area code, of
Registrant's principal executive offices)
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W. Mark Lortz
President and Chief Executive Officer
TheraSense, Inc.
1360 South Loop Road
Alameda, California 94502
(510) 749-5400
(Name, address, including zip code, and telephone number, including area code,
of agent for service)
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Copies to:

Karen A. Dempsey, Esq. Faye H. Russell, Esq.
Alexander D. Phillips, Esq. Jeffrey C. Thacker, Esq.
Helen E. Quinn, Esq. Jason M. Hannon, Esq.
Vicente P. Reyes, Esq. Brobeck, Phleger & Harrison LLP
Wilson Sonsini Goodrich & Rosati 12390 El Camino Real
Professional Corporation San Diego, California 92130
One Market, Spear Street Tower, Suite 3300 (858) 720-2500
San Francisco, California 94105
(415) 947-2000

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Approximate date of commencement of proposed sale to the public: As soon as
practicable after the effective date of this Registration Statement.
If any of the securities being registered on this Form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, check the following box. [_]
If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following
box and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. [_]
If this Form is a post-effective amendment filed pursuant to Rule 462(c) under
the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [_]
If this Form is a post-effective amendment filed pursuant to Rule 462(d) under
the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [_]
If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [_]
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CALCULATION OF REGISTRATION FEE

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Proposed Maximum
Title of Each Class of Proposed Maximum Aggregate
Securities to be Amount to be Offering Price Offering Amount of
Registered Registered (1) Per Share Price (2) Registration Fee (3)
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Common Stock, $0.001 par
value................. 6,900,000 $20.00 $138,000,000.00 $34,500.00
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(1) Includes 900,000 shares which the underwriters have the option to purchase
to cover over-allotments, if any.
(2) Estimated solely for the purpose of computing the amount of the
registration fee pursuant to Rule 457(o) under the Securities Act of 1933,
as amended.
(3) This amount was previously paid.
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The Registrant hereby amends this Registration Statement on such date or dates
as may be necessary to delay its effective date until the Registrant shall file
a further amendment which specifically states that this Registration Statement
shall thereafter become effective in accordance with Section 8(a) of the
Securities Act of 1933 or until the Registration Statement shall become
effective on such date as the Commission acting pursuant to said Section 8(a)
may determine.

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

This amendment incorporates by reference Amendment No. 5 to Registration
Statement on Form S-1 (File No. 333-64456). This amendment is being filed
solely to file Exhibits 10.7, 10.7(b), 10.11, 10.12, 10.14, 10.15 and 10.17
hereto.

II-1

Item 16. Exhibits and Financial Statement Schedules.

(a) Exhibits

Exhibit
Number Description of Document
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*1.1 Form of Purchase Agreement

*3.1(a) Certificate of Incorporation of TheraSense, Inc., a Delaware
corporation, as currently in effect

*3.1(b) Amended and Restated Certificate of Incorporation of TheraSense,
Inc. to be filed upon completion of the offering

*3.2(a) Bylaws of TheraSense, Inc. as currently in effect

*3.2(b) Amended and Restated Bylaws of TheraSense, Inc. as in effect
upon completion of the offering

*4.1 Specimen Common Stock Certificate

*5.1 Opinion of Wilson Sonsini Goodrich & Rosati, Professional
Corporation

*10.1 1997 Stock Plan and forms of agreements thereunder

*10.2 2001 Stock Plan and forms of agreements thereunder

*10.3 2001 Employee Stock Purchase Plan and forms of agreement
thereunder

*10.4 Form of Director and Executive Officer Indemnification Agreement

*10.5 Employment Letter from TheraSense, Inc. to W. Mark Lortz, dated
as of October 6, 1997

*+10.6 Technology Purchase Agreement between TheraSense, Inc. and E.
Heller & Co. dated as of October 10, 2000

+10.7 Cooperative Development Agreement between TheraSense, Inc. and
Facet Technologies LLC (f/k/a Gainor Medical North America LLC),
dated as of December 1, 1998

*10.7(a) First Amendment to Cooperative Development Agreement between
TheraSense, Inc. and Facet Technologies LLC (f/k/a Gainor
Medical North America LLC), effective June 1, 2001.

+10.7(b) Master Purchase Agreement between TheraSense, Inc. and Facet
Technologies LLC effective June 1, 2001.

*10.8 Standard Industrial/Commercial Single-Tenant Lease between
TheraSense, Inc. and PlyProperties, a Partnership, dated as of
February 26, 1999, and addendum thereto

*+10.9 Master Purchase Agreement between TheraSense, Inc. and
Flextronics International USA, Inc., dated as of November 3,
1999

*+10.10 Assignment of Patent Rights and Technology by and among Board of
Regents of the University of Texas System, an agency of the
State of Texas, Dr. Adam Heller and E. Heller & Company dated
August 1, 1991

+10.11 First Amendment, dated March 19, 1998, to the Agreement entitled
Assignment of Patent Rights and Technology by and among Board of
Regents of the University of Texas System, an agency of the
State of Texas, Dr. Adam Heller, E. Heller & Company and
TheraSense, Inc. dated August 1, 1991

II-2

Exhibit
Number Description of Document
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+10.12 License Agreement between TheraSense, Inc. and Asulab SA., dated
February 23, 2000

*+10.13 Warehouse Distribution Contract between TheraSense, Inc. and
Livingston Healthcare Service, Inc., dated March 15, 2000

+10.14 International Distributor Agreement between TheraSense, Inc. and
Nipro Corporation, dated April 1, 2001

+10.15 International Distributor Agreement between TheraSense, Inc. and
Disetronic Handels AG, dated September 13, 2000

*+10.16 Management Services Agreement between TheraSense, Inc. and ICT
Group, Inc., dated January 31, 2000 and revised April 4, 2000

+10.17 License Agreement between TheraSense, Inc. and Unilever PLC dated
February 10, 2000

*10.18 Promissory Note dated March 5, 1999 for the principal aggregate
amount of $72,495 issued by W. Mark Lortz to TheraSense, Inc.

*10.19 Promissory Note dated July 30, 1998 for the principal aggregate
amount of $17,500 issued by Charles T. Liamos to TheraSense, Inc.

*10.20 Promissory Note dated March 5, 1999 for the principal aggregate
amount of $15,187.50 issued by Charles T. Liamos to TheraSense,
Inc.

*10.21 Promissory Note dated September 1, 1999 for the principal
aggregate amount of $61,250 issued by Charles T. Liamos to
TheraSense, Inc.

*10.22 Promissory Note dated December 1, 1997 for the principal aggregate
amount of $62,650 issued by W. Mark Lortz to TheraSense, Inc.

*10.23 Amended and Restated Investors Rights Agreement by and among
holders of TheraSense Preferred Stock and TheraSense, Inc., dated
January 23, 2001, as amended

*10.24 First Amendment to the Agreement Entitled Sponsored Research
Agreement No. UTA 98-0296 entered into as of October 10, 2000, by
and between TheraSense, Inc. and the Board of Regents of the
University of Texas System on behalf of the University of Texas at
Austin.

*10.25 Form of Change of Control Agreement between TheraSense, Inc. and
each Vice President of TheraSense, Inc.

*23.1 Consent of PricewaterhouseCoopers LLP, independent accountants

*23.2 Consent of Counsel (included in exhibit 5.1)

*24.1 Power of Attorney

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+ Confidential treatment has been requested for portions of this
exhibit
* Previously filed

(b) Financial Statement Schedules

The following schedule was previously filed:

Schedule II--Valuation and Qualifying Accounts

Other schedules for which provision is made in the applicable accounting
regulations of the Securities and Exchange Commission are not required under
the related instructions or are inapplicable, and therefore have been omitted.

II-3

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended,
TheraSense, Inc. has duly caused this Amendment No. 6 to the Registration
Statement on Form S-1 to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Alameda, State of California, on the 10th day
of October, 2001.

THERASENSE, INC.

/s/ W. Mark Lortz
By: _________________________________
W. Mark Lortz
President and Chief Executive
Officer

Pursuant to the requirements of the Securities Act of 1933, as amended, this
Amendment No. 6 to the Registration Statement on Form S-1 has been signed by
the following persons in the capacities and on the dates indicated.

Signature Title Date
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/s/ W. Mark Lortz President, Chief Executive October 10, 2001
______________________________________ Officer and Director
W. Mark Lortz (Principal Executive Officer)

/s/ Charles T. Liamos Chief Financial Officer and October 10, 2001
______________________________________ Vice President (Principal
Charles T. Liamos Financial and Accounting
Officer)

*Annette J. Campbell-White Director October 10, 2001
______________________________________
Annette J. Campbell-White

*Mark J. Gainor Director October 10, 2001
______________________________________
Mark J. Gainor

*Ross A. Jaffe, M.D. Director October 10, 2001
______________________________________
Ross A. Jaffe, M.D.

*Michael M. McNamara Director October 10, 2001
______________________________________
Michael M. McNamara

*Robert R. Momsen Director October 10, 2001
______________________________________
Robert R. Momsen

*Ephraim Heller Director October 10, 2001
______________________________________
Ephraim Heller

*Richard P. Thompson Director October 10, 2001
______________________________________
Richard P. Thompson

/s/ W. Mark Lortz
*By: ____________________________
W. Mark Lortz
(Attorney-In-Fact)

II-4

EXHIBIT INDEX