We hope you enjoyed our posts about the World Congress for Hair Research held in Seoul, South Korea, and our series on platelet-rich plasma (PRP). We want to say hello to our new subscribers and welcome you to our exciting journey of learning about hair!

Today, we will answer 4 questions about LPP management, dutasteride in pre-menopausal women, and spironolactone dosing for FPHL.

Disclaimer: For educational purposes only. Not medical advice. Please consult your dermatologist before making any changes to your treatment.

Reader question: “Should chemical sunscreens be avoided in patients with LPP/FFA or to prevent these conditions?”

Avoid benzophenone-3 (oxybenzone) as it is considered an endocrine disruptor.

Reader question: “Are JAK inhibitors or isotretinoin for LPP a good idea?”

I don’t like isotretinoin in LPP, so I definitely prefer JAK inhibitors.

Reader question: “If a pre menopausal woman has an IUD and uses condoms, can dutasteride ever be considered as a treatment option?”

I discuss that if she desires to be pregnant, she needs to wait at least 6 months after treatment interruption.

Reader question: “Optimal Spironolactone dosing for female pattern hair loss?”

100 to 200 mg

If this Q&A was useful to you:

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• Drop a comment with follow-up questions.

• Please let us know what else you would like to see from us! We love hearing from you!

See you next week!

— Dr. Antonella Tosti (@Dr.TostiandLeeHair)

It was wonderful to connect with many of you at the World Congress of Hair Research in Seoul, South Korea. It’s always inspiring to learn from colleagues around the world, and we look forward to continue sharing new hair research and innovations.

Today, we will answer 3 questions about lichen planopilaris (LPP), minoxidil in androgenetic alopecia (AGA), and corticosteroid scalp injections (intralesional vs intramuscular).

Disclaimer: For educational purposes only. Not medical advice. Please consult your dermatologist before making any changes to your treatment.

Reader question: “Best treatment for LPP?”

There are no randomized clinical trials that can answer this question. I will list my first-line treatments, but this reflects my personal experience. First line: hydroxychloroquine, low-dose naltrexone, ILK. Second line: JAKs, Mycophenolate mofetil, Pioglitazone. A new study is now recruiting patients in the US. This study (the ALPINE study) evaluates once-a-day brepocitinib (an oral selective TYK2/JAK1 dual inhibitor) vs placebo.

Reader question: “In your experience, what is the best treatment to halt the progression of LPP, and additionally, which biologic or JAK inhibitor has demonstrated the most favorable outcomes in the control of this disease?”

I don’t recommend biologic. TNF-alpha inhibitors can even trigger LPP. Among JAKs most data are with tofacitinib, less with baricitinib, but results are not as consistent as with alopecia areata. There is a new study now recruiting patients in the US. This study (the ALPINE study) evaluates once-a-day brepocitinib (an oral selective TYK2/JAK1 dual inhibitor) vs placebo.

Reader question: “Can we start minoxidil in an AGA patient with a positive hair pull test even after 3 to 4 months of cyclical therapy?”

Yes, you can, but advise the patient that the shedding can increase at the beginning of treatment.

Reader question: “Thoughts on using intramuscular kenalog instead of intralesional kenalog if patients are averse to scalp injections?”

Intramuscular Kenalog has considerably higher risks of side effects as compared with the injections and can be utilized occasionally, but not with the 6 weeks frequency we utilize the injections. It may be an option in patients with active progressing disease, but not in the case of established patches. Don’t use more frequently than once a month for a maximum of 3-4 months.

If this Q&A was useful to you:

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• Drop a comment with follow-up questions.

• Please let us know what else you would like to see from us! We love hearing from you!

See you next week!

— Dr. Antonella Tosti (@Dr.TostiandLeeHair)

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We hope you enjoyed our series on Eyelashes this week. Today, we will answer 3 follow-up questions from our previous posts on minoxidil-induced facial hypertrichosis, injectables for AGA, and grey hair reversal.

This week, we will finish the Eyelashes series, cover Cancer & Hair, and share the latest updates from the 14th World Congress for Hair Research (WCHR 2026) held this coming weekend in Seoul, South Korea.

Disclaimer: For educational purposes only. Not medical advice. Please consult your dermatologist before making any changes to your treatment.

Reader question: “Have you found bicalutamide to be effective for reducing minoxidil-induced facial hypertrichosis, and if so, how effective, how long does it take, etc.?”

Yes, but only for facial hair. Other body areas do not respond. You can either start medications at the same time or add bicalutamide (my dose is 50 mg every other day) when the hypertrichosis develops. Improvement requires at least 3-4 months.

Reader question: “I saw your post about injectables for androgenetic alopecia. When it comes to delivery methods, which is generally more effective: mesotherapy or micro-infusions with tattoo machine (MMP)?”

I don’t think there is a real difference in results, and we don’t have a comparative study. MMP delivery requires more time than mesotherapy, but provides more uniform depth and distribution and is less operator-dependent.

Reader question: “I have had patients ask about Arey Hair Care. I’ve reviewed the website and ingredients and would love your thoughts on the ingredients’ ability to reverse and slow greying. It is pricy for my patients, so I am hesitant to recommend something unless I have proof it is efficacious.”

The important ingredient, besides antioxidants, is Palmitoyl Tetrapeptide-20 (PTP20), an α-MSH mimetic peptide that activates MC1-R (the main melanogenesis receptor), increases melanogenic markers such as TRP-1, TRP-2, and Melan-A, reduces ASIP expression, enhances catalase activity with reduction of intracellular H₂O₂ levels, and activates SIRT1 (a longevity/stress-response pathway).

PTP20 is therefore one of the few cosmetic anti-gray peptides with mechanistic data supporting activation of hair pigmentation pathways and reduction of oxidative stress. However, clinical evidence remains limited, and there is only 1 published study that demonstrates histologic changes within hair follicles but has no images of repigmentation of established white hair.

Short answer is : the biologic rationale is interesting, but clinical evidence is weak.

If this Q&A was useful to you:

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• Drop a comment with follow-up questions.

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— Dr. Antonella Tosti (@Dr.TostiandLeeHair)

Thank you so much for subscribing! Substack is where we answer questions we receive.

We hope you enjoyed our recent Menopause & Hair series on Instagram. Today, we will answer questions about treatments and screening for menopausal and postmenopausal women.

This week, we are excited to kick off a new series on Eyebrows & Eyelashes. Follow us on Instagram to stay up to date on the latest research and Dr. Tosti’s clinical pearls!

Disclaimer: For educational purposes only. Not medical advice. Please consult your dermatologist before making any changes to your treatment.

Reader question: “How do you counsel postmenopausal female patients on risks/adverse effects of dutasteride given the lack of published data on this topic?”

I feel that dutasteride is safe in postmenopausal women, and side effects such as reduced sexual drive or anxiety are uncommon. Recent data indicate that exposure to 5α-reductase inhibitors does not increase the risk of breast or gynecologic cancers in women.

Reader question: “Do you ever treat postmenopausal women with BOTH dutasteride/finasteride AND spironolactone?”

Yes, I do. Mechanism of action is different, and I like this association in women with Hamilton pattern FPHL.

Reader question: “Do you recommend more frequent mammograms outside of the normal recommendations (other other year); for example yearly, if a woman is on finasteride? And what if she is >74 ?”

No. There are two recent letters published on JAAD showing that 5-alpha reductase inhibitors do not increase the risk of breast cancer, but they can instead decrease this risk.

If this Q&A was useful to you:

• Subscribe so you don’t miss the upcoming individual posts.

• Drop a comment with follow-up questions.

• Please let us know what else you would like to see from us! We love hearing from you!

See you next week!

— Dr. Antonella Tosti (@Dr.TostiandLeeHair)

Disclaimer: For educational purposes only. Not medical advice. Consult your dermatologist before making any changes to your treatment.

1. Telogen Effluvium - Questions Regarding Treatments & Pregnancy

Reader question: “For patients with acute telogen effluvium, if they want to start oral minoxidil, how long should they remain on it? And after stopping do they lose hair gradually or does that only apply if they have concomitant AGA?

If the patient has just acute telogen effluvium and the cause has been found and removed, I stop oral minoxidil after 4 to 6 months. Gradually is better. In the case of acute telogen effluvium associated with AGA, it should be maintained in the long-term.

Reader question: “What do you recommend in patients whose telogen effluvium does not respond with any therapy or procedure?”

If telogen effluvium does not respond to treatment, you are likely dealing with chronic telogen effluvium (CTE). The most important step is patient counseling. Explain that this is a hair cycle disorder, the shed hair grows back of the same thickness, there is no miniaturization and they will not go bald. However, volume may not fully return to baseline. For treatment, oral minoxidil is currently the best option.

Reader question: “For premenopausal women with chronic TE and/or AGA, how do you support their hair when they need to stop everything during pregnancy? Is there anything that can support their hair during pregnancy safely?”

The only treatment I feel safe in pregnant women is low level light therapy even though there are no published data on this topic. I do not recommend nutriceuticals in pregnant women.

Reader question: “Can you please discuss use of LDOM for TE or AGA in pre menopausal women who will be child bearing? Is there any argument for use of same if it’s only for short term use. Will it worsen their hair loss if they stop the LDOM when pregnant? Or will the impact be more helpful than the shedding they will get when they discontinue LDOM?”

Everything depends on timing. If they plan to get pregnant in a few months, I don’t start oral minoxidil. I would rather recommend LLLT that can be continued during pregnancy. If they plan a pregnancy in 1 year, start low dose oral minoxidil (LDOM).

If this Q&A was useful to you:

• Subscribe so you don’t miss the upcoming individual posts.

• Drop a comment with follow-up questions.

• Please let us know what else you would like to see from us! We love hearing from you!

See you next week!

— Dr. Antonella Tosti (@Dr.TostiandLeeHair)

Let’s get into it.

Disclaimer: For educational purposes only. Not medical advice. Consult your dermatologist before making any changes to your treatment.

1. FFA and personal care products: Do we still avoid fragrances and facial SPF if patch testing was unremarkable?

Reader question: “For your patients with FFA, what are your thoughts on using personal hygiene products / avoiding certain ingredients if their patch testing was unremarkable? Do you still avoid fragrances or facial SPF?”

I recommend that patients with Frontal Fibrosing Alopecia (FFA) use fragrance-free shampoos and conditioners.

I also advise the use of zinc oxide-based sunscreens, while avoiding:

· Titanium dioxide (INCI: Titanium Dioxide, CI 77891)

· Oxybenzone (INCI: Benzophenone-3)

Similarly, patients should avoid foundations and cosmetic products containing titanium dioxide, as well as root touch-up sprays, which frequently include this ingredient.

I do not routinely perform patch testing, as I do not believe this represents a contact allergy but rather a possible toxic effect of these ingredients.

2. Is Capixyl safe during pregnancy, postpartum, and breastfeeding? And does it have lasting effects after you stop?

Reader question: “I would like to ask Dr Tosti what her opinion is of hair growth products that contain Capixyl, whether these are safe for use during pregnancy, post partum and breastfeeding mums, and whether they have lasting effects once ceased?”

“Thoughts on regular use of Capixyl in breastfeeding and pregnant women?”

Capixyl is a cosmetic product composed of a biomimetic peptide combined with red clover extract, which is rich in Biochanin A.

Biochanin A is the major isoflavone found in red clover (Trifolium pratense) and has been shown to inhibit both type I and type II 5α-reductase.

For this reason, I do not recommend its use during pregnancy or in women who are trying to conceive. Inhibition of 5α-reductase may in fact interfere with the normal development of the male fetal genitalia.

I do not recommend Capixyl in postpartum hair loss either. Its formulation targets androgen-dependent mechanisms, which are not involved in telogen effluvium.

There is no data that Capixyl is safe during breastfeeding, so I recommend avoiding it as well.

3. How do I manage telogen effluvium in menopausal patients who need hormone replacement therapy?

Reader question: “Dr. Tosti, how do you manage telogen effluvium in menopausal patients who require hormone replacement therapy?”

I don’t think HRT is an aggravating factor for telogen effluvium. It may actually help in prolonging the anagen phase.

I manage postmenopausal women with TE with

• Oral minoxidil

• “Scalp patting”: multimodal procedure combining iontophoresis, mechanical stimulation, and LLLT

A note on the questions we didn’t get to today

Thank you to everyone who submitted a question. We answered 3 today, but plan on answering the rest of the questions soon, along with the papers that support those answers.

Future topics will cover

• LPP, TE, AGA, Injectables for AGA, Hair loss treatments in postmenopausal female patients, and more!

If this Q&A was useful to you:

• Subscribe so you don’t miss the upcoming posts.

• Drop a comment with follow-up questions.

See you in our next post.

— Dr. Antonella Tosti (@Dr.TostiandLeeHair)

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Dr. Antonella Tosti - World-Renowned Hair Expert (published 800+ articles, 15+ hair books, trained 100+ dermatologists around the 🌎, organizes 3+ hair meetings a year, sees hair patients daily). Fredric Brandt Endowed Professor of Dermatology and Cutaneous Surgery at the University of Miami. Former president of the European Hair Research Society and American Hair Research Society. When she is not traveling around the world for conferences, she resides in Miami.

Soon-to-be Dr. Juwon Lee - Hair fellow for Dr. Antonella Tosti, has collaborated on many hair projects since 2022. Passionate about advancing innovation and increasing healthcare access with AI. Grew up in South Korea and California. MD at the University of Miami (Class of 2026). Speaks Korean, English, Spanish, and is learning Chinese.

Our goal is to make hair dermatology knowledge more accessible for dermatologists & patients using social media and AI. Combining our different backgrounds, we hope our page serves as a bridge across generations and cultures. Follow along for the latest hair research and clinical pearls drawn from decades of Dr. Tosti’s experience treating hair patients!

Follow us on Instagram: @dr.tostiandleehair

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