Minocycline (antibiotic) boosts 5AR/DHT (in gingival fibroblasts)

Came across this, found it interesting to note that minocycline (an antibiotic) increased 5AR activity (albeit in Gingival fibroblasts inthe mouth).

Note: The tissues that surround and support the teeth are collectively called the periodontium.

ncbi.nlm.nih.gov/pubmed/9477 … PlusDrugs1

Effects of the anti-androgen finasteride on 5alpha-reductase activity in human gingival fibroblasts in response to minocycline.

Soory M, Virdi H.
Department of Periodontology, King’s College School of Medicine & Dentistry, London, United Kingdom.

In addition to their antimicrobial properties, tetracyclines have antiinflammatory and pro-anabolic effects on the reparatory potential of connective tissue and bone.

The physiologically active androgen 5alpha-dihydrotestosterone (DHT) implicated in matrix synthesis is formed in gingivae from androgen substrates.

The aim of this investigation is to study the androgen metabolic response of gingivae to minocycline, in the presence or absence of the anti-androgen finasteride. Chronically inflamed gingival tissue derived from 12 subjects aged 30-50 years and passaged fibroblasts derived from this source, were used for the experiments.

Duplicate incubations were performed in Eagle’s MEM with 14C-testosterone/14C-4-androstenedione in the presence or absence of minocycline (5-60 microg/ml) or finasteride for 24 h.

The androgen substrate 14C-testosterone was metabolised mainly to DHT and 4-androstenedione, while 14C-4-androstenedione was converted mainly to DHT and testosterone.

Minocycline at 20-30 microg/ml stimulated the formation of these metabolites from both substrates by 13-25%. In the tissue incubations there were 3- and 2-fold increases in DHT and 4-androstenedione formation (n=12; p<0.01).

The anti-androgen finasteride caused significant inhibition of 5alpha-reductase activity on both substrates at 0.1 & 1.0 microg/ml with total inhibition at 10 & 50 microg/ml (n=3; p<0.01). Minocycline-induced stimulation of 5alpha-reductase activity was also inhibited by finasteride (n=4; p<0.02).

Since finasteride inhibition of 5alpha-reductase activity is specific for the type 2 isoenzyme associated with anabolic functions of target tissue, this enzyme activity may contribute to some of the cited anabolic tissue responses to minocycline.

PMID: 9477022 [PubMed - indexed for MEDLINE]

ncbi.nlm.nih.gov/pubmed/1070 … 20Propecia

The effect of minocycline on the metabolism of androgens by human oral periosteal fibroblasts and its inhibition by finasteride.

Soory M, Tilakaratne A.
Department of Periodontology, GKT Dental Institute, King’s College, Caldecot Road, London, UK.

The antimicrobial minocycline has matrix-stimulatory effects on connective tissue and bone. The aim here was to study the effect of minocycline on 5alpha reduction of androgen substrates to 5alpha-dihydrotestosterone (DHT) in periosteal fibroblasts and the influence of the antiandrogen finasteride on this conversion.

Confluent cultures of periosteal fibroblasts established from oral periosteum isolated from the bone surface were incubated in duplicate in multiwell dishes with two androgen substrates, [(14)C]-testosterone/[(14)C]-4-androstenedione, in the presence or absence of serial concentrations of minocycline or the antiandrogen finasteride or the two in combination for 24 h.

The metabolites formed were solvent-extracted with ethyl acetate, separated by thin-layer chromatography and quantified using a radioisotope scanner. Both androgen substrates were metabolized to DHT and 4-androstenedione or testosterone.

Minocycline stimulated the synthesis of DHT from these substrates by 75-83% at 20-30 microg/ml (n=4; p<0.01). Finasteride inhibited the 5alpha-reductase activity of these substrates by 3-5-fold at 1 microg/ml and 40-80% at 0.01 and 0.1 microg/ml (n=4; p<0.01), with little change in 17beta-hydroxysteroid dehydrogenase activity.

Minocycline and finasteride in combination showed an intermediate response with one substrate.

As finasteride inhibits the type 2, 5alpha-reductase isoenzyme associated with anabolic functions, these findings demonstrate target-tissue androgen metabolic activity in periosteal fibroblasts at baseline and in response to minocycline.

This has implications for the reparatory potential of the diseased periodontium during adjunctive treatment with minocycline.

PMID: 10708666 [PubMed - indexed for MEDLINE]

This is fascinating as I took antibiotics after this finmess and have been recovering…could be coincidental. Interesting anyway.

My antibiotic was Tetralycal lymecyclin

Doing some more research, turns out this drug is often given to clear up acne… I’m confused however, since acne is often under androgen (ie, DHT) control… if minocycline increases DHT, how could this be help clear up acne?

aocd.org/skin/dermatologic_d … cline.html


On the other hand, even though it may clear up Acne, anecdotally seems it might in fact increase DHT --> hairloss, as noted by comments at bottom of this page. … cd=6&gl=ca

It clears up Acne because sometimes Acne is caused by a bacterial infection. Particularly, the P. Acnes bacterium is at fault for this. Minocycline, a tetracyclic semi-synthetic antibiotic, targets this bacteria and other gram-positive bacteria. Therefore, destroying the infectious bacteria can alleviate Acne.

Would this include bad breath as a possible effect, or is it possible that finasteride could cause halitosis?

This makes sense. A month ago i had to have my wisdom tooth pulled. I took Amoxiciline for 10 days (don’t know if it is the same kind of antibiotic). I don’t know if it is a coincidence but since then my balls come close to my body when i masturbate (the skin contracts, when i am “excited”). Before that it always hung loose no matter what.

On the other hand, i now realize, it is since that time that my depression worsened, so i don’t understand.

This is most likely a coincidence.

Minocycline is a semi-synthetic tetracycline antibiotic, which are characterized by their four carbon rings (tetra = 4) within the chemical structures.

Amoxicillin, on the other hand, is in a completley different class of antibiotics known as the penecillins (itself being a beta-lactam antibiotic) which acts on different bacteria, using different methods (i think cell lysis), and producing different side effects.

So Amoxicillin would not have the same effects.

I actually took that exact antibiotic Minocyclin to clear up my acne for about a year or two back in high school/college (around 2002 to 2005) – took time off it. I didn’t really notice a huge difference in acne being cleared up but perhaps worked a little.

Minocycline looks intriguing as a 5AR increaser hmm. I am wondering, if this does increase 5AR as indicated, is my current consumption of things that supposedly reduce DHT (soy, broccoli, green tea, etc.) hindering my efforts in recovery?

I’ve had acne before, during, and after Propecia. Being on Propecia for 58 days did nothing positively or negatively to my acne. And I think I have some sort of OCD with body appearance, so I would most certainly notice that.

Very interesting Mew…oxytetracycline was what I used to take during my spotty teenager stage. It worked by inhibiting sebum production.

is anyone getting results ftom this cycline now? TO be sure, I’ve experiienced some hardness after taking some antibiotics in the past .


If this antibiotic is prescribed for acne i would think it was fairly mild… although i thought the same thing about propecia.

Still, from all the substances that we know of that increase 5ar2, this seems to be the safest although does anyone have any idea as to whether it only increases the activity of 5ar2 in the mouth or throughout the body? It seems unlikely that it would cause a localised effect.

Yeah, i know what you mean solonjk, why the fuck can’t there just be a way to restore our 5ar2 that doesn’t involve taking another, potentially harmful drug?

Does azithromycin have the same effect? I am sick in bed but feel maybe 25% recovered. It’s really quite remarkable. It could be a coincidence too, I suppose. I hope I can hold onto this feeling.


Found this thread while searching whether green tea was good or bad. Read something a few times that it could raise estrogen/estradiol. Since caffeine messes with sleepy time (and as I could sleep deeper and longer, my sides improved) green tea/extract is a no vote from me.

But, anyways… I never bothered to mention in my previous posts that I started 100mg of minocycline once a day, about a month ago. Looks like it might help my propecia recovery. I got the script for perioral dermatitis… which I’ve had for years and has improved 50% already.

Can’t really say if it helped in my recovery… I’m pretty good these days - 85%ish. Hard to tell slight changes at this stage.

I will say this though… I always had a bit of nagging groin tenderness on my right side, which I thought was work related. It’s completely gone, now. I’m wondering if the antibiotic helped clear that up.

Has anyone tried this yet or brought up the idea to one of the PFS docs?

I think this does relate to me:

I can tell you is, my teeth were better a year ago pre fin. I was at my dentist and she was surprised that my teeth were in worse condition then ever before eventho i only drink water and dont use any sugar at all.
I wish I had had these to print out and give her. Well, next time.

Minocycline has a “superior ability to cross the blood-brain barrier” (fin crosses the BBB also). At first glance this seems promising, however a look at the side effect list is scary.


Despite the promise, I advise everyone to seriously read through the side effects before considering this chemical antibiotic (it doesn’t occur in nature). There are reports that many of the side effects listed may become persistent similar to accutane and finasteride side effects. As both accutane and minocycline are synthetic and used to treat acne, with many of the same side effects, this should be approached with extreme caution.

I was on Minocycline pre and post Saw Palmetto and RU (Androgen blocker) and I swear my symptoms greatly worsened after I stopped this past October. I gained about 15 lbs of fat since I stopped, despite a low carb diet and 6 days of pretty vigorous workouts a week. Also, I am getting tons of cystic acne on my head, shoulders and chest since. And also I have flu like symptoms that will not go away since Xmas. I was on 100mg 2x a day.

I’m going to my Endo on Thursday and am going to see if she can prescribe it for me again. This is a kind of old thread, but has anyone else seen any positive effects of Minocycline?

So I’ve been on Minocycline again for about a month, nothing new to report. I’m actually getting more acne (which is maybe a good sign?) but no other noticeable changes in physical or mental sides.