The treatment of baldness has remained an unsolved problem for decades. Androgenetic alopecia affects 80% of men and 35% of women at some point in their lives. There are two options, which have remained the same for eternity: minoxidil (variable effectiveness, daily use) or finasteride (sexual and neurological side effects).
Absci has used AI to engineer an antibody that targets the prolactin receptor, shifting follicles from the dormant phase to the growth phase. This isn't a slowing of hair loss; it's actual regrowth. Six months after the injection, the macaques had full hair. This injectable hair loss treatment also solves the problem of adherence: one dose every few months instead of daily creams or pills. Let's get straight to the point: human trials begin in December 2025, with results expected by mid-2026. And then? And then, and then... Meanwhile, let's take a (very small) step back to explain everything properly.
The needle built by artificial intelligence
AbsciVancouver-based biotech company has used artificial intelligence to build what people normally search for tentatively. ABS-201 it is a computer-designed antibody which affects the prolactin receptor (PRLR), a protein involved in breast development but also in the hair cycle. No other drug works this way. The prolactin receptor had never been considered a serious target for baldness. Until now..
The mechanism is simple, on paper. Hair follicles enter the telogen (dormant) phase and remain there. On healthy skin, a new hair grows after the old hair falls out. In those with androgenetic alopecia, the follicle remains dormant. Period.
What does ABS-201 do, instead? It moves follicles from the telogen phase to the anagen phase (active growth). It doesn't slow hair loss: it rekindles the follicle.
The traditional approach to drug development is like looking for a needle in a haystack: trial, error, years. Absci He used AI to directly construct it. A huge number of computer simulations allowed him to optimize the antibody's potency, reduce the risk of immune reactions, and shorten the timeframe. The result: 24 months of development instead of five years, 15 million dollars of investment instead of 100.
Six months and the macaques had all their hair
Preclinical tests tell more than promises. The team of Absci tested ABS-201 on macaques, primates that shed hair like us. Six months after the injection, the macaques had complete regrowthNot patchy, not partial. Complete.
In mice, the results were even faster. After 22 days, complete regrowth with ABS-201Minoxidil, in the same experiment, only worked on a third of the mice. The difference is not subtle.
There is one detail worth noting. ABS-201 not only regrows hair, but also repigments gray hair in macaques. The hair turned black again. It wasn't the primary goal of the study, but it happened. A positive side effect that could pave the way for a different approach. As I was saying some time ago, research on gray hair is intertwined with that on cellular aging.
An injection every few months, not daily creams
The injectable form solves a practical problem. Minoxidil and finasteride require daily use. People forget, get tired, and quit. GLP-1 inhibitors for diabetes and obesity (such as the now very famous Ozempic) have cleared the injectables through customs.
Sean McClainCEO Absci, says it clearly: GLP-1s have paved the way. An injection every few months is easier to remember and digest than a regimen based on a cream or a pill every day.
ABS-201 also avoids the so-called "initial shedding" phase of minoxidil. What is it? Those who try minoxidil lose hair in the first few weeks. This is normal, but discouraging. Many stop before seeing results. With ABS-201, according to preclinical data, this does not happen. The follicles reactivate without experiencing an accelerated shedding phase.
Phase 1/2a clinical trials to begin in December 2025 in Australia, under the supervision of Rodney Sinclair, a dermatologist and the world's leading expert on alopecia. Initial safety and efficacy results are expected in the second half of 2026. If the data holds up, ABS-201 could be on the market within a few years.
The landscape of hair loss treatment is changing
ABS-201 is not alone, and we are following all the cutting-edge research in this field for you. There is a gel based on deoxyribose (DNA sugar) which showed 80-90% regrowth in mice. There is PP405, a topical drug that reawakens follicle stem cells. There are JAK inhibitors such as baricitinib, approved in Italy for alopecia areata. Research is converging on one point: in almost all cases, the follicles aren't dead, they're dormant. And they can be awakened.
A technical but significant detail. A 2025 study showed that adipose stem cells combined with ATP (adenosine triphosphate) produced 100% regrowth in male mice and 90% in females with DHT-induced alopecia. ATP improves stem cell metabolism, enhancing their regenerative capacity. This is a different approach than ABS-201, but it confirms the direction: working on metabolism and cell signaling works.
Hair loss treatment: what to expect (and what not to expect)
ABS-201 is probably not a cure for those who have been completely bald for decades. Completely atrophied follicles will not reactivate. The drug works on miniaturized but still present follicles. Those with early-stage alopecia, or those with advanced stages but progressive thinning, will be ideal candidates for this hair loss treatment.
Human trials, of course, will reveal much. And there's work to be done: safety, dosage, frequency of injections, and actual efficacy in both men and women. The data on macaques are encouraging, but confirmation is needed. The leap from primates to humans is not a given. Anthony Rossi, dermatologist at Memorial Sloan Kettering Cancer Center and partners of Absci, he is cautious but optimistic. No other drug affects the prolactin receptor in this way.
If all goes as planned, ABS-201 could be the first treatment that not only slows hair loss but also reactivates growth. This is no small promise for those who have tried minoxidil, finasteride, and transplants, with only partial or no results. As I wrote years agoBaldness isn't just a cosmetic issue. It affects self-esteem, relationships, and psychological well-being.
The trials will tell whether ABS-201 is truly a breakthrough or just another cruel reversal.
