What is the best topical treatment for hair loss?
Clinically reviewed by
Finasteride, dutasteride and minoxidil are the most popular medications used to treat male pattern baldness, or androgenetic alopecia (AGA). While each was originally formulated as an oral dose drug, finasteride, dutasteride and minoxidil have all since been developed into topical treatments.
Solutions, gels, creams, foams and sprays can be used to transport these medications into your body via the skin. But apart from this functional similarity, these different mediums range in appearance, product composition, consistency and how they move through various layers of skin and tissue.
When mapping out your hair growth journey, it’s important that you understand why some formulations are better suited than others to target your hair loss. Here, we brief you on some of the factors that differentiate topical drug vehicles.
Do topical drugs need to be absorbed into the bloodstream?
Finasteride and dutasteride do not need to be absorbed into the bloodstream to target hair loss. In fact, the risk of experiencing sexual side effects from these medications increases greatly once absorption has occurred and the drug effect is more widespread (Lee et. al 2018).
To effectively target hair loss, finasteride and dutasteride have to reduce the concentration of a hormone called dihydrotestosterone (DHT) within the scalp skin. Drug action can be targeted at the hair follicles using precision pharmaceutical treatments, such as compounded Topical Finasteride, with SiloxysSystem™ gel.
Precision drug delivery avoids eliciting a systemic effect often associated with a higher risk of side effects – when drug action occurs throughout the body. Topical finasteride can target hair loss when drug action is localized, or contained within specific layers of tissue within the scalp.
How does finasteride target hair follicles?
Topical formulations containing finasteride need to penetrate just beyond the outermost layer of scalp skin to target hair follicles. Again, this drug does not actually need to travel into the bloodstream to reach the target destination.
Hair follicles only extend about 4mm below the surface of the scalp skin, anchored in the outermost epidermis and dermis beneath (NIH). Administered topically, finasteride is generally processed by the body at a set rate within these cellular layers.
Why does topical formulation matter?
Many topical formulations push finasteride into target cell membranes faster than the body can process it; any surplus travels into deeper layers of tissue. This means that less finasteride remains within the scalp where it can be effective and more of the active ingredient makes its way into the bloodstream.
The composition of a topical carrier largely determines how quickly the drug moves into the body and the degree of movement into the body it can achieve. Both of these factors influence how the body processes medications administered via the skin and impact the overall effect of the active ingredient. These variables can also impact the drug's side effect profile.
How do different types of topicals compare?
The most popular topical carriers for drugs targeting hair loss are solutions, sprays, foams and gels. Various gel formulations tend to be the preferred medium for compounded topical finasteride and dutasteride. Solutions, sprays and foams are the most widely available forms of minoxidil.
Composition, function, viscosity, feel and appearance range between different types of topical formulations. Even topicals of the same type – two gels, for example – can have dramatically different constitutions. All of these factors influence how the topical drug moves into the skin. By adjusting formulation, a topical can penetrate just past the surface layer of the skin, permeate into deeper layers of tissue or it can be absorbed into the bloodstream.
Penetration: transporting finasteride into the skin
A topical has penetrated the skin once it has moved past the outermost layer (the epidermis) and into the body. Penetration implies that a topical remains within the top level of skin and doesn’t move into deeper layers of tissue.
It can be difficult to regulate the movement of a topical enough to drastically affect its degree of permeation. But it can be done with the right formulation.
Some topical formulations permeate across cellular membranes and through multiple layers of tissue, pushing the active ingredient deeper into the body. Ingredients called penetration-enhancing agents aid in this effort by accelerating movement into the skin.
Alcohol is the most popular penetration-enhancing agent in topical drugs, used to transport the active ingredient into more central tissue. Solutions, sprays and foams generally contain a higher concentration of alcohol than most gel formulations.
Other non-medicinal ingredients that accelerate absorption include dimethylsulfoxide (DMSO), ethoxydiglycol and propylene glycol. Although formulations vary by brand, topical medications for AGA often contain one or more of these as key ingredients.
Without the right formulation, it can be difficult to regulate the movement of a topical enough to actually minimize the degree of permeation. Penetration-enhancing agents are meant to reduce the amount of time it takes for the topical to pass through the skin, but the name can be misleading. Many topical drug formulations that boast enhanced penetration actually achieve enhanced permeation through multiple tissue layers and can unintentionally wind up in the bloodstream.
Permeation: delivering finasteride to the hair follicle
The skin is rich in oils called lipids, which protect the outermost layer and help control permeation into deeper tissue. Liposomes are round, synthetic molecules that are able to move past this lipid layer and permeate into cell membranes thanks to their composition. Used in topical drug formulations, these phospholipid molecules that can enhance the movement of drugs like finasteride into certain types of tissue. Topical gels formulated with liposomes help ensure that finasteride permeates through the epidermis and reaches the dermis, where it can target DHT at the hair follicles.
While liposomal gels are a step up from topical carriers formulated without these molecular vessels, many miss the mark. Most liposomal gels ensure that finasteride makes its way to the target tissue, but aren’t able to regulate the rate that the drug is released into the body. Similar to topicals formulated with penetration-enhancing agents, liposomal gels risk flooding the scalp skin with more finasteride than it can process at once.
What is the best topical vehicle for finasteride?
With topical finasteride, the key to preventing unnecessary absorption into the bloodstream is regulating the rate of movement across the outermost skin barrier. Recall: finasteride is processed by the body at a set rate. Ensuring that finasteride is released into the body at a rate that affords the body time to process the drug, without overwhelming the system.
Most topical formulations carry the active ingredient through multiple layers of tissue faster than the body is able to process it, thus increasing the likelihood of absorption – bad news. This effect is amplified when a formulation contains multiple penetration-enhancing agents, or a higher concentration of these ingredients. Compounded finasteride gels containing liposomes might also have this effect without the addition of certain components to counter a large influx of the drug.
Certain topical formulations can regulate the degree of absorption into the body by delaying the rate at which finasteride enters through the skin. XYON’s compounded Topical Finasteride, with SiloxysSystem™ Gel contains liposomes to enhance permeation into target cell membranes in addition to two types of lab-synthesized silicone to reduce the rate of movement into the body.
It’s important to consider how each type of topical vehicle transports finasteride into the body, the rate at which the active ingredient is released into the body and the effect that each specific formulation is intended to have.
Topical vehicles that aim to contain drug action within a specific layer of the skin can optimize the therapeutic effect and minimize the risk of experiencing side effects. Not all topical formulations are equal.
Alfredo, Rossi, et al. Minoxidil Use in Dermatology, Side Effects and Recent Patents. Recent Patents on Inflammation & Allergy Drug Discovery, vol. 6, no. 2, May 2012, pp. 130–36, https://www.eurekaselect.com/96626/article.
Antihypertensive Agents. Antihypertensive Agents, 2 Feb. 2011, https://www.cancer.gov/publications/dictionaries/cancer-terms/def/antihypertensive-agent.
Carrer, Victor, et al. Effect of Propylene Glycol on the Skin Penetration of Drugs. Archives of Dermatological Research, vol. 312, no. 5, July 2020, pp. 337–52, doi:10.1007/s00403-019-02017-5.
Diffusion Cell Apparatus. https://orchidscientific.com/product/diffusion-cell-apparatus/
Enzymes and Energetics. W.B. Saunders, 2012, doi:10.1016/B978-0-323-07446-9.00004-0
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). The Role of 5-Alpha Reductase in Mediating Testosterone Actions. Clinical trial registration, NCT00070733, clinicaltrials.gov, 4 Nov. 2005, https://clinicaltrials.gov/ct2/show/NCT00070733
Hasson & Wong. Male Pattern Hair Loss - Hair Loss In Men. Hasson & Wong, https://hassonandwong.com/hair-loss/male-pattern-baldness-hair-loss/
Hulin-Curtis SL, Petit D, Figg WD, Hsing AW, Reichardt JK. Finasteride metabolism and pharmacogenetics: new approaches to personalized prevention of prostate cancer. Future Oncol. 2010;6(12):1897-1913. doi:10.2217/fon.10.149
Lanigan, Rebecca S., and Torill A. Yamarik. Final Report on the Safety Assessment of BHT. International Journal of Toxicology, vol. 21 Suppl 2, 2002, pp. 19–94, doi:10.1080/10915810290096513
Lee, Sung Won, et al. A Systematic Review of Topical Finasteride in the Treatment of Androgenetic Alopecia in Men and Women. Journal of Drugs in Dermatology : JDD, vol. 17, no. 4, Apr. 2018, pp. 457–63, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609098/
Minoxidil. ISHRS, 26 July 2018, https://ishrs.org/patients/treatments-for-hair-loss/medications/minoxidil/
Morton, David A., et al. “Chapter 15. Scalp, Skull, and Meninges.” The Big Picture: Gross Anatomy, The McGraw-Hill Companies, 2011, accessmedicine.mhmedical.com/content.aspx?aid=8666891
NCBI. Propylene Glycol. https://pubchem.ncbi.nlm.nih.gov/compound/1030
Salisbury, Blake H., and Prasanna Tadi. 5 Alpha Reductase Inhibitors. StatPearls, StatPearls Publishing, 2021, http://www.ncbi.nlm.nih.gov/books/NBK555930/
Tajran, Jahan, and Amanda A. Gosman. Anatomy, Head and Neck, Scalp. StatPearls, StatPearls Publishing, 2021, http://www.ncbi.nlm.nih.gov/books/NBK551565/
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