POWER OF ATTORNEY
	Know all by these presents that the undersigned hereby constitutes and appoints
each of James B. Bucher of Alder BioPharmaceuticals, Inc. (the "Company") and
Alan Hambelton, Julia Stark and Brian Woodard of Cooley LLP, signing
individually, the undersigned's true and lawful attorneys-in fact and agents to:
	(1)	prepare, execute in the undersigned's name and on the undersigned's behalf,
and submit to the Securities and Exchange Commission (the "SEC") a Form ID,
including amendments thereto, and any other documents necessary or appropriate
to obtain codes and passwords enabling the undersigned to make electronic
filings with the SEC of reports required by Section 16(a) of the Securities
Exchange Act of 1934 or any rule or regulation thereunder;

	(2)	prepare, execute in the undersigned's name and on the undersigned's behalf,
and submit to the SEC Forms 3, 4 and 5 (including amendments thereto and joint
filing agreements in connection therewith) in accordance with Section 16(a) of
the Securities Exchange Act of 1934 and the rules thereunder;

	(3)	do and perform any and all acts for and on behalf of the undersigned that
may be necessary or desirable to prepare and execute any such Form 3, 4 or 5
(including amendments thereto and joint filing agreements in connection
therewith) and file such Forms with the SEC and any stock exchange,
self-regulatory association or any other authority; and

	(4)	take any other action of any type whatsoever in connection with the
foregoing that, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required of the undersigned, it being
understood that the documents executed by the attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as the attorney-in-fact may approve in the
attorney-in-fact's discretion.

	The undersigned hereby grants to each such attorney in fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney in fact, or such attorney
in fact's substitute or substitutes, shall lawfully do or cause to be done by
virtue of this power of attorney and the rights and powers herein granted.  The
undersigned acknowledges that the foregoing attorneys-in-fact, and their
substitutes, in serving in such capacity at the request of the undersigned, are
not assuming (nor is the Company assuming) any of the undersigned's
responsibilities to comply with Section 16 of the Securities Exchange Act of
1934.

	This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
Company and the attorneys-in-fact.  This Power of Attorney revokes any other
power of attorney that the undersigned has previously granted to representatives
of the Company and Cooley LLP.

	IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of the date written below.

Dated:  April 12, 2018


By: /s/ Erin Lavelle						Erin Lavelle
	Signature					Printed Name