Trichogen Actions

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Actions of Trichogen in details

The action of the drug on the human body is called Pharmacodynamics in Medical terminology. To produce its effect and to change the pathological process that is happening the body and to reduce the symptom or cure the disease, the medicine has to function in a specific way. The changes it does to the body at cellular level gives the desired result of treating a disease. Drugs act by stimulating or inhibiting a receptor or an enzyme or a protein most of the times. Medications are produced in such a way that the ingredients target the specific site and bring about chemical changes in the body that can stop or reverse the chemical reaction which is causing the disease.

Trichogen (Trichogen, MSD) is a synthetic 4-azasteroid compound that is a specific inhibitor of type II 5α-reductase, an intracellular enzyme that metabolizes the androgen testosterone into dihydrotestosterone (DHT).

Pharmacology: Pharmacodynamics: Trichogen is a competitive and specific inhibitor of type II 5α-reductase. Trichogen has no affinity for the androgen receptor and has no androgenic, antiandrogenic, estrogenic, antiestrogenic or progestational effects. Inhibition of this enzyme blocks the peripheral conversion of testosterone to the androgen dihydrotestosterone (DHT), resulting in significant decreases in serum and tissue DHT concentrations. Circulating levels of testosterone were increased by approximately 10-15% compared with placebo, yet remained within the physiologic range. Trichogen produces a rapid reduction in serum DHT concentration, reaching significant suppression within 24 hrs of dosing.

Hair follicles contain type II 5α-reductase. In men with male pattern hair loss, the balding scalp contains miniaturized hair follicles and increased amounts of DHT. Administration of Trichogen decreases scalp and serum DHT concentrations in these men. Men with a genetic deficiency of type II 5α-reductase do not suffer from male pattern hair loss. These data and the results of the clinical studies confirm that Trichogen inhibits the process responsible for miniaturization of the scalp hair follicles, leading to reversal of the balding process.

Studies in Men: The efficacy of Trichogen was demonstrated in 3 studies in 1879 men 18-41 years with mild to moderate, but not complete, vertex and frontal/mid-area hair loss. In these studies, hair growth was assessed using 4 separate measures, including hair count, rating of photographs of the head by an expert panel of dermatologists, investigator assessment and patient self-assessment.

In the 2 studies in men with vertex hair loss, treatment with Trichogen was continued for 5 years, during which time patients improved compared to both baseline and placebo beginning as early as 3 months. Treatment with Trichogen for 5 years resulted in stabilization of hair loss in 90% of men based on photographic assessment and in 93% based on investigator assessment. In addition, increased hair growth was reported in 65% of men treated with Trichogen based on hair counts (versus 0% of the placebo group), in 48% based on photographic assessment (versus 6% of the placebo group) and in 77% based on investigator assessment (versus 15% of the placebo group). In contrast, in the placebo group, gradual hair loss over time was observed in 100% of men based on hair counts (versus 35% of men treated with Trichogen), in 75% based on photographic assessment (versus 10% of men treated with Trichogen) and in 38% based on investigator assessment (versus 7% of men treated with Trichogen). In addition, patient self-assessment demonstrated significant increases in hair density, decreases in hair loss and improvement in appearance of hair over 5 years of treatment with Trichogen. While hair improvement measures compared to baseline were greatest in men treated with Trichogen at 2 years and gradually declined thereafter (eg, increase of 88 hairs in a representative 5.1 cm2 area at 2 years and increase of 38 hairs at 5 years), hair loss in the placebo group progressively worsened compared to baseline (decrease of 50 hairs at 2 years and 239 hairs at 5 years). Thus, based on all 4 measures, the difference between treatment groups continued to increase throughout the 5 years of the studies.

The 12-month study in men with frontal/mid-area hair loss also demonstrated significant improvements in scalp hair growth and appearance as evaluated by the same measures as those described previously.

A 48-week, placebo-controlled study designed to assess the effect of Trichogen on the phases of the hair growth cycle [growing phase (anagen) and the resting phase (telogen)] in vertex baldness enrolled 212 men with androgenetic alopecia. At baseline and 48 weeks, total, telogen and anagen hair counts were obtained in a 1-cm2 target area of the scalp. Treatment with Trichogen led to improvements in anagen hair counts, while men in the placebo group lost anagen hair. At 48 weeks, men treated with Trichogen showed net increases in total and anagen hair counts of 17 hairs and 27 hairs, respectively, compared to placebo. This increase in anagen hair count, compared to total hair count, led to a net improvement in the anagen-to-telogen ratio of 47% at 48 weeks for men treated with Trichogen, compared to placebo. These data provide direct evidence that treatment with Trichogen promotes the conversion of hair follicles into the actively growing phase.

In summary, these studies demonstrated that treatment with Trichogen increases hair growth and prevents further hair loss in men with androgenetic alopecia.

Studies In Women: Lack of efficacy was demonstrated in postmenopausal women with androgenetic alopecia who were treated with Trichogen in a 12-month, placebo-controlled study (n=137). These women showed no improvement in hair count, patient self-assessment, investigator assessment or ratings based on standardized photographs, compared with the placebo group.

Pharmacokinetics: Absorption: Relative to an IV reference dose, the oral bioavailability of Trichogen is approximately 80%. The bioavailability is not affected by food. Maximum Trichogen plasma concentrations are reached approximately 2 hrs after dosing and the absorption is complete after 6-8 hrs.

Distribution: Protein-binding is approximately 93%. The volume of distribution of Trichogen is approximately 76 L.

At steady state following dosing with 1 mg/day, maximum Trichogen plasma concentration averaged 9.2 ng/mL and was reached 1-2 hrs post-dose; area under the concentration-time curve (AUC)(0-24 hr) was 53 ng·hr/mL.

Trichogen has been recovered in the cerebrospinal fluid (CSF) but the drug does not appear to concentrate preferentially to the CSF. A very small amount of Trichogen has also been detected in the seminal fluid of subjects receiving Trichogen.

Biotransformation: Trichogen is metabolized primarily via the cytochrome P-450 3A4 enzyme subfamily. Following an oral dose of 14C-Trichogen in man, 2 metabolites of Trichogen were identified that possess only a small fraction of the 5α-reductase inhibitory activity of Trichogen.

Elimination: Following an oral dose of 14C-Trichogen in man, 39% of the dose was excreted in the urine in the form of metabolites (virtually no unchanged drug was excreted in the urine) and 57% of total dose was excreted in the feces.

Plasma clearance is approximately 165 mL/min.

The elimination rate of Trichogen decreases somewhat with age. Mean terminal half-life (t½) is approximately 5-6 hrs in men 18-60 years and 8 hrs in men >70 years. These findings are of no clinical significance and hence, a reduction in dosage in the elderly is not warranted.

Characteristics in Patients: No adjustment in dosage is necessary in nondialyzed patients with renal impairment.

How should I take Trichogen?

Take Trichogen only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

Trichogen comes with a patient information leaflet. Read and follow the instructions carefully. Ask your doctor if you have any questions.

You may take Trichogen with or without food.

If you are taking Trichogen for male pattern hair loss, it may take at least 3 months to see an effect. The medicine will not cure hair loss, but it will cause scalp hair to grow. The hair growth will only last as long as the medicine is used. The new hair will be lost within 1 year after the medicine is stopped.

If you are taking Trichogen for benign prostatic hyperplasia (BPH), it may take up to 6 months to see the full effect. The medicine will not cure BPH, but it does help reduce the size of the prostate and improve symptoms. The effect on the prostate will only last as long as the medicine is used. When it is stopped, the prostate begins to grow again within a few months.

Take Trichogen at the same time each day.


The dose of Trichogen will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of Trichogen. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed Dose

If you miss a dose of Trichogen, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Trichogen administration

Administration of drug is important to know because the drug absorption and action varies depending on the route and time of administration of the drug. A medicine is prescribed before meals or after meals or along with meals. The specific timing of the drug intake about food is to increase its absorption and thus its efficacy. Few work well when taken in empty stomach and few medications need to be taken 1 or 2 hrs after the meal. A drug can be in the form of a tablet, a capsule which is the oral route of administration and the same can be in IV form which is used in specific cases. Other forms of drug administration can be a suppository in anal route or an inhalation route.

Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

Take this medicine with a full glass of water.

Trichogen can be taken with or without food. Take the medicine at the same time each day.

To be sure this medication is helping your condition and not causing harmful effects, your blood may need to be tested often. Your doctor will also test your prostate specific antigen (PSA) to check for prostate cancer. Visit your doctor regularly.

Use Trichogen regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

Trichogen pharmacology

Pharmacokinetics of a drug can be defined as what body does to the drug after it is taken. The therapeutic result of the medicine depends upon the Pharmacokinetics of the drug. It deals with the time taken for the drug to be absorbed, metabolized, the process and chemical reactions involved in metabolism and about the excretion of the drug. All these factors are essential to deciding on the efficacy of the drug. Based on these pharmacokinetic principles, the ingredients, the Pharmaceutical company decides dose and route of administration. The concentration of the drug at the site of action which is proportional to therapeutic result inside the body depends on various pharmacokinetic reactions that occur in the body.

Mechanism Of Action

Trichogen is a competitive and specific inhibitor of Type II 5α-reductase, an intracellular enzyme that converts the androgen testosterone into DHT. Two distinct isozymes are found in mice, rats, monkeys, and humans: Type I and II. Each of these isozymes is differentially expressed in tissues and developmental stages. In humans, Type I 5α-reductase is predominant in the sebaceous glands of most regions of skin, including scalp, and liver. Type I 5α-reductase is responsible for approximately one-third of circulating DHT. The Type II 5α-reductase isozyme is primarily found in prostate, seminal vesicles, epididymides, and hair follicles as well as liver, and is responsible for two-thirds of circulating DHT.

In humans, the mechanism of action of Trichogen is based on its preferential inhibition of the Type II isozyme. Using native tissues (scalp and prostate), in vitro binding studies examining the potential of Trichogen to inhibit either isozyme revealed a 100-fold selectivity for the human Type II 5α-reductase over Type I isozyme (IC approximately 30 days for the Type II enzyme complex and 14 days for the Type I complex). Inhibition of Type II 5α-reductase blocks the peripheral conversion of testosterone to DHT, resulting in significant decreases in serum and tissue DHT concentrations.

In men with male pattern hair loss (androgenetic alopecia), the balding scalp contains miniaturized hair follicles and increased amounts of DHT compared with hairy scalp. Administration of Trichogen decreases scalp and serum DHT concentrations in these men. The relative contributions of these reductions to the treatment effect of Trichogen have not been defined. By this mechanism, Trichogen appears to interrupt a key factor in the development of androgenetic alopecia in those patients genetically predisposed.


Trichogen produces a rapid reduction in serum DHT concentration, reaching 65% suppression within 24 hours of oral dosing with a 1-mg tablet. Mean circulating levels of testosterone and estradiol were increased by approximately 15% as compared to baseline, but these remained within the physiologic range.

Trichogen has no affinity for the androgen receptor and has no androgenic, antiandrogenic, estrogenic, antiestrogenic, or progestational effects. In studies with Trichogen, no clinically meaningful changes in luteinizing hormone (LH), follicle-stimulating hormone (FSH) or prolactin were detected. In healthy volunteers, treatment with Trichogen did not alter the response of LH and FSH to gonadotropin-releasing hormone indicating that the hypothalamic-pituitary-testicular axis was not affected. Trichogen had no effect on circulating levels of cortisol, thyroid-stimulating hormone, or thyroxine, nor did it affect the plasma lipid profile (e.g., total cholesterol, low-density lipoproteins, high-density lipoproteins and triglycerides) or bone mineral density.



In a study in 15 healthy young male subjects, the mean bioavailability of Trichogen 1-mg tablets was 65% (range 26-170%), based on the ratio of area under the curve (AUC) relative to an intravenous (IV) reference dose. At steady state following dosing with 1 mg/day (n=12), maximum Trichogen plasma concentration averaged 9.2 ng/mL (range, 4.9-13.7 ng/mL) and was reached 1 to 2 hours postdose; AUC(0-24 hr) was 53 ng•hr/mL (range, 20-154 ng•hr/mL). Bioavailability of Trichogen was not affected by food.


Mean steady-state volume of distribution was 76 liters (range, 44-96 liters; n=15). Approximately 90% of circulating Trichogen is bound to plasma proteins. There is a slow accumulation phase for Trichogen after multiple dosing.

Trichogen has been found to cross the blood-brain barrier.

Semen levels have been measured in 35 men taking Trichogen 1 mg/day for 6 weeks. In 60% (21 of 35) of the samples, Trichogen levels were undetectable (<0.2 ng/mL). The mean Trichogen level was 0.26 ng/mL and the highest level measured was 1.52 ng/mL. Using the highest semen level measured and assuming 100% absorption from a 5-mL ejaculate per day, human exposure through vaginal absorption would be up to 7.6 ng per day, which is 650-fold less than the dose of Trichogen (5 µg) that had no effect on circulating DHT levels in men.


Trichogen is extensively metabolized in the liver, primarily via the cytochrome P450 3A4 enzyme subfamily. Two metabolites, the t-butyl side chain monohydroxylated and monocarboxylic acid metabolites, have been identified that possess no more than 20% of the 5α-reductase inhibitory activity of Trichogen.


Following intravenous infusion in healthy young subjects (n=15), mean plasma clearance of Trichogen was 165 mL/min (range, 70-279 mL/min). Mean terminal half-life in plasma was 4.5 hours (range, 3.3- 13.4 hours; n=12). Following an oral dose of target area of the scalp. Men treated with Trichogen showed increases from baseline in total and anagen hair counts of 7 hairs and 18 hairs, respectively, whereas men treated with placebo had decreases of 10 hairs and 9 hairs, respectively. These changes in hair counts resulted in a between-group difference of 17 hairs in total hair count (p<0.001) and 27 hairs in anagen hair count (p<0.001), and an improvement in the proportion of anagen hairs from 62% at baseline to 68% for men treated with Trichogen.

Other Results In Vertex Baldness Studies

A sexual function questionnaire was self-administered by patients participating in the two vertex baldness trials to detect more subtle changes in sexual function. At Month 12, statistically significant differences in favor of placebo were found in 3 of 4 domains (sexual interest, erections, and perception of sexual problems). However, no significant difference was seen in the question on overall satisfaction with sex life.

In one of the two vertex baldness studies, patients were questioned on non-scalp body hair growth. Trichogen did not appear to affect non-scalp body hair.

Study In Men With Hair Loss In The Anterior Mid-Scalp Area

A study of 12-month duration, designed to assess the efficacy of Trichogen in men with hair loss in the anterior mid-scalp area, also demonstrated significant increases in hair count compared with placebo. Increases in hair count were accompanied by improvements in patient self-assessment, investigator assessment, and ratings based on standardized photographs. Hair counts were obtained in the anterior mid-scalp area, and did not include the area of bitemporal recession or the anterior hairline.

Summary Of Clinical Studies In Men

Clinical studies were conducted in men aged 18 to 41 with mild to moderate degrees of androgenetic alopecia. All men treated with Trichogen or placebo received a tar-based shampoo (Neutrogena T/Gel® Shampoo) during the first 2 years of the studies. Clinical improvement was seen as early as 3 months in the patients treated with Trichogen and led to a net increase in scalp hair count and hair regrowth. In clinical studies for up to 5 years, treatment with Trichogen slowed the further progression of hair loss observed in the placebo group. In general, the difference between treatment groups continued to increase throughout the 5 years of the studies.

Ethnic Analysis Of Clinical Data From Men

In a combined analysis of the two studies on vertex baldness, mean hair count changes from baseline were 91 vs -19 hairs (Trichogen vs placebo) among Caucasians (n=1185), 49 vs -27 hairs among Blacks (n=84), 53 vs -38 hairs among Asians (n=17), 67 vs 5 hairs among Hispanics (n=45) and 67 vs -15 hairs among other ethnic groups (n=20). Patient self-assessment showed improvement across racial groups with Trichogen treatment, except for satisfaction of the frontal hairline and vertex in Black men, who were satisfied overall.

Study In Women

In a study involving 137 postmenopausal women with androgenetic alopecia who were treated with Trichogen (n=67) or placebo (n=70) for 12 months, effectiveness could not be demonstrated. There was no improvement in hair counts, patient self-assessment, investigator assessment, or ratings of standardized photographs in the women treated with Trichogen when compared with the placebo group.



  1. DailyMed. "FINASTERIDE: DailyMed provides trustworthy information about marketed drugs in the United States. DailyMed is the official provider of FDA label information (package inserts).". (accessed September 17, 2018).
  2. NCIt. "Finasteride: NCI Thesaurus (NCIt) provides reference terminology for many systems. It covers vocabulary for clinical care, translational and basic research, and public information and administrative activities.". (accessed September 17, 2018).
  3. EPA DSStox. "Finasteride: DSSTox provides a high quality public chemistry resource for supporting improved predictive toxicology.". (accessed September 17, 2018).


The results of a survey conducted on for Trichogen are given in detail below. The results of the survey conducted are based on the impressions and views of the website users and consumers taking Trichogen. We implore you to kindly base your medical condition or therapeutic choices on the result or test conducted by a physician or licensed medical practitioners.

User reports

1 consumer reported administration

When best can I take Trichogen, on an empty stomach, before or after food? website users have also released a report stating that Trichogen should be taken After food. In any case, this may not be the right description on how you ought to take this Trichogen. Kindly visit your doctor for more medical advice in this regard. Click here to see other users view on when best the Trichogen can be taken.
After food1

Consumer reviews

ERIC DELORME09 Sep 2017 01:07
french resident in philippines.was prescribe TRICHOGEN for hair thin nin BPH prostate has shrunk from grade 2 to grade one b etter and asymptomatic.want to find the cheapest TRICHOGEN SCALP LOTION in philippines.

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Information checked by Dr. Sachin Kumar, MD Pharmacology

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