UNITEDSTATES

SECURITIESAND EXCHANGE COMMISSION

Washington,D.C. 20549

FORM8-K

CURRENTREPORT

PURSUANTTO SECTION 13 OR 15(d) OF THE

SECURITIESEXCHANGE ACT OF 1934

Dateof Report (Date of Earliest Event Reported): July 24, 2024

PROTAGENICTHERAPEUTICS, INC.

(Exactname of Company as specified in its charter)

212-994-8200

(Company’stelephone number, including area code)

(Formername or former address, if changed since last report)

Checkthe appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Company under anyof the following provisions:

Securitiesregistered pursuant to Section 12(b) of the Act:

Item3.01 Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

OnWednesday, July 24, 2024, Protagenic Therapeutics, Inc. (“the Company”) received a deficiency letter (the “NotificationLetter”) from the Nasdaq Listing Qualifications (“Nasdaq”) stating that it is not in compliance with the minimum bidprice requirements set forth in Nasdaq Listing Rule 5550(a)(2) for continued listing on The Nasdaq Capital Market. Nasdaq Listing Rule5550(a)(2) requires listed securities to maintain a minimum bid price of $1.00 per share, and Nasdaq Listing Rule 5810(c)(3)(A) providesthat a failure to meet the minimum bid price requirement exists if the deficiency continues for a period of 30 consecutive business days.Based on the closing bid price of the Company’s common stock for the 30 consecutive business days prior to the date of the NotificationLetter, the Company no longer meets the minimum bid price requirement. The Notification Letter has no immediate effect on the listingor trading of the Company’s common stock on the Nasdaq Capital Market and, at this time, the common stock will continue to tradeon the Nasdaq Capital Market under the symbol “PTIX”.

TheNotification Letter states that the Company has 180 calendar days, or until January 20, 2025, to regain compliance with Nasdaq ListingRule 5550(a)(2). To regain compliance, the Company’s closing bid price of the Company’s common stock must have a closingbid price of at least $1.00 for a minimum of ten consecutive business days.

Theletter further states that in the event the Company does not regain compliance by January 20, 2025, the Company may be eligible for anadditional 180 days if it meets the continued listing requirement for market value of publicly held shares and all other initial listingstandards for Nasdaq, with the exception of the bid price requirement, and will need to provide written notice of its intention to curethe deficiency during the second compliance period. If the Company does not qualify for the second compliance period or fails to regaincompliance during the second compliance period, Nasdaq will provide written notification to the Company that its common stock is subjectto delisting. At that time, the Company may appeal the delisting determination to a hearings panel pursuant to the procedures set forthin the applicable Nasdaq Listing Rules. However, there can be no assurance that, if the Company does appeal the delisting determinationby Nasdaq to the panel, such appeal would be successful.

SIGNATURES

Pursuantto the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf bythe undersigned hereunto duly authorized.