Stockholders' equity (Details)		1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Mar. 11, 2024 USD ($) $ / shares shares	Apr. 30, 2025 shares	Jun. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2025 USD ($) Vote $ / shares shares	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) $ / shares shares	Nov. 08, 2024 USD ($)	Jan. 26, 2024 USD ($)
Common stock
Stock, shares authorized | shares			440,000,000	440,000,000
Common stock, shares authorized | shares			400,000,000	400,000,000		400,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001		$ 0.001
Preferred stock, shares authorized | shares			40,000,000	40,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001
Number of voting rights per common share | Vote				1
Stock based compensation expense			$ 100,000	$ 300,000	$ 200,000
Shelf Registration Statement
Proceeds from issuance of common stock				459,019	15,999,598
Common stock issuance costs				18,291	$ 1,310,953
March 2024 Private Placement
Warrant exercises				$ 0		$ 0
Common Stock
Common stock
Conversion of preferred stock into common stock (in shares) | shares		12,516
Series A Convertible Preferred Stock
Common stock
Conversion of preferred stock into common stock (in shares) | shares		25,033
Convertible preferred stock, shares outstanding | shares			31,194	31,194		56,227
Number of shares remained to be converted into common stock | shares			15,596	15,596		28,112
March 2024 Private Placement | Pre-funded Warrants
March 2024 Private Placement
Warrants to purchase of shares | shares			507,076	507,076
March 2024 Private Placement | Purchasers | Securities purchase agreement
Shelf Registration Statement
Shares issued | shares	1,687,712
Common stock issuance costs	$ 1,300,000
March 2024 Private Placement
Offering price per share | $ / shares	$ 7.29
Common stock with an exercise price | $ / shares	$ 0.001
Percentage of outstanding shares	4.99%
Proceeds from sale of common stock in a private placement	$ 16,000,000
Expected gross proceeds from potential future warrants cash exercise	$ 18,000,000
March 2024 Private Placement | Purchasers | Securities purchase agreement | At the election of holder
March 2024 Private Placement
Percentage of outstanding shares	9.99%
March 2024 Private Placement | Purchasers | Securities purchase agreement | Pre-funded Warrants
March 2024 Private Placement
Offering price per share | $ / shares	$ 7.289
Warrants to purchase of shares | shares	507,076
March 2024 Private Placement | Purchasers | Securities purchase agreement | Tranche A Warrants (Pre-funded Warrants Exercise Price 7.29 Per Share)
March 2024 Private Placement
Warrants to purchase of shares | shares	1,097,394
Common stock with an exercise price | $ / shares	$ 7.29
Stock issuance anniversary period	3 years
Number of days after announcement of Phase 2 dose for ATRN-119	30 days
Volume weighted average price | $ / shares	$ 14.58
Number of consecutive trading days	30 days
March 2024 Private Placement | Purchasers | Securities purchase agreement | Tranche B Warrants (Pre-funded Warrants Exercise Price 9.1125 Per Share)
March 2024 Private Placement
Common stock with an exercise price | $ / shares	$ 9.1125
Stock issuance anniversary period	5 years
Number of days after announcement of Phase 2 dose for ATRN-119	30 days
Volume weighted average price | $ / shares	$ 18.225
2024 Shelf Registration Statement
Shelf Registration Statement
Maximum amount to be issued under universal shelf registration statement								$ 150,000,000
Maximum amount to be issued under at-the-market offering program								1,000,000
Maximum amount to be issued under at-the-market offering program, supplement							$ 3,000,000	2,000,000
2024 Shelf Registration Statement | HCW
Shelf Registration Statement
Maximum amount to be issued under at-the-market offering program							$ 3,000,000
2024 ATM offering
Shelf Registration Statement
Shares issued | shares			220,733	243,139		41,152
Proceeds from issuance of common stock			$ 400,000	$ 400,000		$ 100,000
Common stock issuance costs			$ 15,000	$ 18,000		$ 6,000
2024 ATM offering | HCW
Shelf Registration Statement
Maximum amount to be issued under at-the-market offering program								$ 2,000,000