ABS-201, Absci, Prolactin

Absci ABS-201: Targeting the Prolactin Receptor

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Absci (US) is an artificial intelligence (AI) drug and biologic creation company that is developing novel treatments via the use generative AI. One of the key products that they are focusing on is a prolactin receptor (PRLR) targeting injection based hair growth treatment called ABS-201. Phase 1 clinical trials for this product began in Australia at Sinclair Dermatology in December 2025.

Note that Hope Medicine (China)’s Phase 1 clinical trials for its competing prolactin receptor blocking HMI-115 injections also occurred at Sinclair Dermatology in 2022. Hope Medicine later completed Phase 2 trials in China in 2025. The company’s HMI-115 was licensed from Germany’s Bayer (whose patent was approved in 2019). So there is a lengthy history of research behind this concept of targeting the prolactin receptor to reverse hair loss.

The original version of this post is at the bottom. New updates are on top.

Update: June 24, 2026

Absci Raises $100 Million from Eli Lilly and others

After the below good news on Absci’s interim Phase 1 data for ABS-201, the publicly traded company raised $100 million via a common stock offering. The fundraising was led by Eli Lilly (US), the largest pharmaceutical company in the US. The funds will be used for both the hair loss and endometriosis programs. Subsequently, Absci’s stock rose by 36%.

Considering the early stage of Absci’s ABS-201 clinical trial progression, this is even more impressive than: Veradermics raising $150 million in Serie C Financing in 2025; and Pelage raising $120 million in Series B Financing in 2025. Both Pelage and Veradermics are currently in Phase 3 trials.

Update: June 24, 2026

Absci Announces Positive Interim Phase 1 Data

Absci just reported positive interim Phase 1 data from its first-in-human trial of ABS-201, an investigational anti-prolactin receptor (PRLR) antibody. The press release does not mention that this trial is taking place in Australia. The data comprises 32 healthy adult participants (with and without androgenetic alopecia) enrolled into four planned single ascending dose (SAD) cohorts. Dose levels evaluated were 150 mg, 450 mg, 900 mg and 1800 mg administered intravenously (IV).

Key points:

  • No serious adverse events were reported as of the data cutoff date.
  • The estimated half-life of at least 65 days means that ABS-201 would only need to be injected in patients 2-to-3 time over a 6-month period.
  • The first multiple ascending dose (MAD) of ABS-201 in a cohort of androgenetic alopecia participants has been initiated.
  • The interim proof-of-concept data is anticipated for the second half of 2026. Full proof-of-concept data is expected in early 2027.

Note that the full 227-person Phase 2 clinical trial is expected to be completed in July 2028.

Update: June 22, 2026

Joe Tillman (the Hair Transplant MentorTM) is interviewing Absci CEO Sean McClain today and the video will be released on Wednesday. If any reader has a question he/she would like to ask, please post it in the comments by 2pm PST today!

The recorded interview will be available on Joe’s YouTube channel on Wednesday (I assume in the “Videos” tab of the channel).

A recent article about Absci on seekingalpha is also worth a read.

Update: January 22, 2026

Absci is publishing numerous new videos on its YouTube channel. All of them are very encouraging so far.

Also check out the company’s detailed presentation on ABS-201 from the end of 2025.

Absci ABS-201 Hair Growth
Absci ABS-201 and its hair growth compared to Minoxidil.

Update: December 11, 2025

ABS-201 Regenerates Hair Stem Cells and Promotes Key Growth Modulators

Absci today unveiled new preclinical data for ABS-201. The data was generated using translational human ex vivo scalp models. It demonstrated that ABS-201 stimulates hair growth by regenerating the stem cell niche as well as by promoting additional key growth modulators. The studies were led by Dr. Ralf Paus, who says:

“Our study provides the first evidence that antagonizing prolactin signaling with ABS-201 could open a radically new chapter in future AGA management.”

Among the key findings:

  • ABS-201 significantly inhibits the PRLR signaling pathway.
  • ABS-201 prolongs the anagen phase by blocking catagen, and promoting hair matrix keratinocyte proliferation.
  • In addition, it increases the production of the hair growth-stimulatory growth factors IGF1 and FGF7.
  • ABS-201 protects and expands the hair follicle progenitor cell pool. It inhibits prolactin-induced apoptosis of K15+ stem cells , and increases their proliferation and capacity to generate CD34+ progeny. This is crucial, since the depletion of progenitor cells is a key hallmark of androgenetic alopecia.
  • It facilitates the reconversion of vellus hairs to terminal hairs.

Also of interest, long-time hair loss sufferer and former US soccer superstar Landon Donovan has teamed up with Absci. Way out of leftfield.

Update: December 4, 2025

Absci just announced that the first volunteers have been dosed in their Phase 1/2a HEADLINE study evaluating ABS-201. Absci will host a virtual KOL seminar on Thursday December 11 to discuss further details about this drug and its clinical trials.

Also check out this great detailed interview of Absci founder and CEO Sean McClain with ARK Invest’s legendary Cathie Wood.

Update: October 20, 2025

Absci to Begin Phase 1 Clinical Trials for ABS-201 in December 2025

In a new article about Absci’s ABS-201 hair growth injections that target the prolactin receptor, it is mentioned that Phase 1 clinical trials will begin in Australia in December 2025. The renowned Dr. Rodney Sinclair will oversee the trials at his Sinclair Dermatology clinic. Interestingly, Hope Medicine’s Phase 1 clinical trials for its prolactin receptor blocking HMI-115 injections also occurred in Australia at Sinclair Dermatology in 2022.

Of note, the Absci research team believes that ABS-201 could also cure premature greying by re-pigmenting the hair. This is based on their pre-clincial work on macaques, in which the animals’ hair reverted back from grey to black.

Key quote regarding Absci’s use of AI to develop this product:

“Using AI to develop the needle itself (in this case, the perfect antibody sequence) researchers were able to discover key antibody binding regions that could precisely target the prolactin receptor, thus ceasing hair loss. Using computer simulations, Absci was able to optimize certain drug qualities, including increased potency and decreased likelihood of negative immune response.”

Update: July 11, 2025

The CEO of Absci posted the below Tweet yesterday. The before and after macaque monkey image in there seems identical to the image from Hope Medicine’s HMI-115 and its effect on macaques. Strange. The same image can also be seen in their 2024 R&D document. Both HMI-115 and Absci’s ABS-201 target the prolactin receptor to regrow hair. Hope Medicine has already completed Phase 2 clinical trials, while Absci is yet to commence any human trials.

ABSCI Hair Growth Prolactin
ABSCI ABS-201 Hair Growth Prolactin.

April 6, 2025

Absci is a data-first artificial intelligence drug and biologic creation company that is unlocking novel treatments through the use generative AI. Most interestingly, one of the key products that they are focusing on is a hair growth treatment called ABS-201 that targets the prolactin receptor.

I first heard about the company in January 2025 when Absci received a $20 million investment from chip manufacturer Advanced Micro Devices (AMD). Unlike virtually all new entrants in the hair loss world, Absci has a great website. However, it should be noted that the company originally started operations way back in 2011, under the auspices of founder and CEO Sean McClain.

In March 2025, Absci presented on the subject of AI in dermatology at the Dermatology Innovation Forum. On a related note, in 2022, I wrote a post on AI and machine learning for hair loss drug discovery.

Absci Presentation on ABS-201

Considering that Absci’s pipeline page shows that ABS-201 is yet to even enter Phase 1 clinical trials, I was reluctant to write this post. However a new video presentation (embedded below) that the company uploaded in February 2025 changed my mind. It is titled “Absci R&D Day 2024”. The portion devoted to ABS-201 and hair loss starts at 1:19:40 and lasts for over an hour.

Also check out the company’s case study page on ANS-201. Interestingly, in the notes to the key mechanism of action diagram, they mention that ABS-201 also has the potential to restore hair pigmentation.

Absci currently has over 77,000 square feet of space between:

  • A state-of-the-art wet lab in Vancouver WA (US).
  • An advanced AI research lab in New York City (US).
  • A drug innovation center in Zug (Switzerland).

The company plans to begin Phase 1 clinical trials for ABS-201 in the first half of 2026. Their preclinical model demonstrated improved hair regrowth in comparison to minoxidil.

Absci ABS-201 versus Hope Medicine HMI-115

ABSCI ABS-201 Prolactin
ABSCI ABS-201 artificial intelligence developed prolactin receptor antibody for hair loss. Comparison to Hope Medicine’s HMI-115. Source: Absci.

Note that Absci’s AI-developed ABS-201 is similar to Hope Medicine’s HMI-115 that is currently in Phase 2 trials. The latter prolactin receptor antibody treatment for male and female pattern hair loss was originally developed by Bayer (Germany) who received a patent for it in January 2019. A few months later, Hope Medicine announced a global licensing agreement with Bayer to advance the development of this monoclonal antibody to target the prolactin receptor.

In the above screenshot from Absci’s R&D Day 2024 presentation video, they elaborate on some of the key differences between ABS-201 and HMI-115.

Ulo Personalized Hair Treatments

Artificial Intelligence, RE:YOU

RE:YOU – AI Enabled Discovery of new Molecules to Grow Hair

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RE:YOU. AI-enabled new hair growth molecule discovery.
RE:YOU. AI-enabled new hair growth molecule discovery.

In 2022, I wrote a post about the increasing use of artificial intelligence (AI) to discover new hair loss drugs. This phenomenon has really grabbed attention this week. First, we heard about Absci (US) raising $100 million for its generative AI-developed hair loss drug ABS-201 (after positive interim Phase 1 clinical trial findings). And now I discuss a brand new company called RE:YOU (US).

RE:YOU: AI-Enabled Discovery of Small Molecules for Hair Follicle Rejuvenation

Several days ago, a new US-based company named RE-YOU (or Re:You) was covered in BioSpace. They announced promising preclinical research in relation to the AI-enabled drug discovery of four novel molecules for hair growth. Each of these four molecules targets a distinct biological pathway involved in hair follicle growth and the scalp environment. All four molecules were evaluated in primary human cell systems and human hair follicle organoid models.

Moreover, the scientists behind this discovery published a lengthy pre-print paper in bioRxiv on June 9, 2026. It is titled:

“AI-enabled discovery of small molecules targeting complementary pathways for hair follicle rejuvenation.”

RE:YOU has named the four molecules as follows:

  • NV-623 and NV-624. Both support and “energize” dermal papilla cell viability and proliferation. Each molecule supposedly showed 30% greater hair growth in comparison to minoxidil.
  • NV-273. Inhibits prolyl hydroxylase domain protein 2 (PHD2), activates hypoxia-inducible factor-1α (HIF-1α) and increases secretion of VEGF-A and lactate. All of this is supposed to benefit the scalp hair growth environment, circulation and regenerative signaling. Interestingly, the massively hyped Pelage Pharmaceuticals’ PP405 hair growth product works by boosting lactate production.
  • NV-1065. A non-steroidal inhibitor of 5α-reductase, the enzyme responsible for converting testosterone into dihydrotestosterone (DHT). The later is the key cause of male pattern hair loss. The researchers claim that this molecule suppresses DHT to a similar extent as dutasteride. Amazing if true.

RE:YOU classifies its portfolio of multi-pathway hair growth molecules under the brand name NOVOGRO™.

Someone has written a very lengthy article on minoxidil vs Novogro that might be worth a read. I did not have the time or motivation to go through it as yet.

Key quote from the BioSpace article:

“Using a combination of machine learning, graph neural networks, structure-based virtual screening, and experimental validation, researchers screened more than 20 million compounds and identified four lead candidates with distinct mechanisms of action.”

All of this sounds very interesting due to the involvement of AI-led drug discovery. Especially if the company can deliver something brand new to topically inhibit scalp DHT levels (without causing any of the potential side effects of oral dutasteride).

But at the moment, I remain skeptical and would not be surprised if all we get is yet another new hair loss cosmeceutical product. If the pre-print article gets published in a reputable journal, I will get a bit more interested.

At the bottom of RE:YOU’s home page, they say that:

“A 150+ subject, 6-month, double-blinded, randomized controlled trial comparing NOVOGRO™ -powered serum (NV-273, NV-623, NV-624) with a minoxidil benchmark arm is currently underway.”

They hope that an interim dataset will be available by the end of July 2026. To me, a comparison with finasteride or dutasteride would be more interesting.

Note that this company and the study co-authors are in various ways affiliated with Integrated Biosciences and LK Innovations.