Dear fellow patrons of the life extension arts,
I've been taking Metformin (in the slow release version) for about a
year and a half now, gradually ramping up the dosage in 500mg increments
to 2g - 1g in the morning, 1g in the evening. The ramp up to 2g is
recent though, just a month or so. For most of the time I've been
experimenting with Metformin (about a year and) I've been taking 1.5g - 1
gram in the morning, 500mg in the evening. I may eventually lower my
dosage back to 1.5g depending on how well my body adjusts to 2g.
To prevent long-term B12 deficiency I also supplement with 1000mcg
sublingual b12 daily plus about 750mg of calcium.
Eventually my personal experimentation sort of swept up a small group
(about 6 of us so far) of like-minded friends and family, also
non-diabetics and health-conscious. Now we're all happily
self-medicating with clinically effective doses of Metformin. Yes, we're
all very consciously thumbing our noses at the traditional FDA-approved
dogma that you should only take "medicine" to treat rather than prevent
illness / extend healthy lifespan.
While my personal experimentation eventually led me to be quite
optimistic regarding Metformin's potential to improve health and maybe
even mimic some of the benefits of calorie restriction in a healthy
subject I was initially very cautious about taking the plunge. Thanks to
the prevailing dogma there is precious little data on Metformin's
effects on healthy non-diabetics. Note that I was pretty fit to begin
with. I work out on average about 80 minutes 3 times a week in a mix of
high-intensity aerobic (3km in 10 minutes) and anerobic (mostly weight
lifting).
FWIW, I read pretty much everything I could get my hands on and even
bought the scientific handbook ("Metformin - the gold standard") to
better understand what I could expect with regards to side effects and
dosage.
I finally decided to start taking Metformin after becoming convinced
that it had an excellent safety profile. The effective dose is about 5%
of the lethal dose (based on animal studies and attempted suicides).
IMHO, the fears regarding lactic acidosis were blown way out of
proportion based on the effects of other biguanidines such as
phenformin. For Metformin you get about 1 incident of lactic acidosis
per 100,000 years of use and even that only seems to happen in patients
with advanced renal failure - exactly the population of people that are
prone to lactic acidosis regardless of whether or not they take
Metformin.
Bottom line, my interpretation of the data was that plain old exercise
looks awfully dangerous compared with Metformin. Everybody knows
exercise is good for you, but if the exact same benefits and risks
(fatal heart failure, spinal injuries, knee damage, increased risk of
lactic acidosis, etc.) were somehow packaged into a pill there's a good
chance it would never be approved according to the prevailing
hyper-conservative one-size-fits-all criteria for drug evaluation that's
choking any real progress in medicine. Imagine what the computer
industry would look like if any advance had to pass anything resembling
FDA regulation. We'd still be stuck in the 1970s.
OK, back on the subject - I had been reading up on Metformin for a
couple of years before finally deciding to self-experiment. I was
tempted by Metformin's inhibition of liver glucogenesis, activation of
AMPK, inhibition of mTOR (like rapamycin), the research that it can
induce mitochondrial bio-genesis, reduced endogenous reactive oxygen
species and associated DNA damage, statistically significant long-term
reduction in cancer and Alzheimer rates, etc. I won't bother citing all
of the research. If you're interested in the evidence, Google it.
Despite my confidence in Metformin's advantage, I decided to be extra
cautious and ramp up my dosage gradually while doing regular blood work
every couple of months - full spectrum tests (blood glucose, hba1c,
lipid levels, blood counts, liver enzymes, testosterone level, etc.),
plus more frequent testing (initially several times a day) of blood
sugar levels using a personal glucose meter.
Better safe than sorry, curiosity killed the cat and all that. Speaking
of curiosity I have to admit that played a large part in my decision to
experiment after I became sufficiently convinced I wasn't risking much
safety-wise.
The results so far:
- initial gastrointestinal discomfort which quickly subsides: I found
this initially to be significant side-effect with the regular
fast-release version of Metformin, even at small doses (e.g., 500mg).
This was significantly less of an issue with the slow release version.
This side-effect seems to go away once the bioflora in your gut
rebalances. This adverse response to a change in dosage (in both
directions) seems to have lasted just a few days for most of the
people in my small experimental group. Using the slow release version,
plus ramping up the dosage slowly seems to help one get acclimatized
with fewer side-effects.
- reduced (but still safe) levels of blood sugar (average,
post-prandial, hba1c): I had been keeping a good diet (no sugars,
complex carbs, decent amounts of protein for a weight-lifter) before
and throughout my experimentation. I wasn't expecting my average BG to
drop dramatically because I wasn't diabetic. If anything I was
concerned Metformin would tip me into hypoglycemia. Many antidiabetic
drugs are very dangerous for non-diabetics for that reason.
Thankfully to the best of my knowledge that never happened. Blood
glucose levels were decreased, but the lowest I ever measured, after
ramping up the dosage while fasting for 12 hours (while awake) was
70mg/dl.
Fasting blood glucose after sleep before I started taking Metformin
was about 90mg/dl. On Metformin around 70-80mg/dl depending mostly on
the exact timing of the test (probably something to do with the
cortisol spike after waking).
Last time I checked my hba1c I was somewhat disappointed to discover
it wasn't as low as I had expected - about 5.2% but I had been playing
with my diet back then and varying my Metformin doses. I'll be testing
again in two months after letting my body adjust to a steady
2000mg/day.
- appetite suppression and incidental calorie restriction: I experienced
a significant dose-dependent suppression of appetite and thus the
number of consumed calories. This effect was significant enough to
make me suspect that at least some of the benefits of Metformin may be
explained by the effects of "accidental" calorie restriction.
The effect is very dramatic in my case. I've tried reducing the dosage
of Metformin to 500mg or 1000mg while consuming the same amount of
calories I am comfortable with at 1500mg and the hunger eventually
drives me up the wall. This increased my respect for CRONners that
manage to basically starve themselves with nothing more than sheer
willpower. Whoever you are, wherever you are, you have my respect. I'm
personally quite sensitive to hunger and couldn't stand the effect on
my quality of life.
With Metformin reducing calories was far easier. A happy unexpected
side effect.
On a side note, this effect on my appetite improved my quality of life
significantly. Before I would have to eat every 4 hours or so to avoid
being driven to distraction by hunger - a trait my family and friends
took great amusement in, considering I've always been rather lean
("where does all that food go?"). Whenever I came over to visit my
parents they'd complain I was eating them out of house and home.
With Metformin I could comfortably go for much longer (6-8 hours)
stretches between meals. Also, the suppression of appetite seems to
dependent on the number of consumed calories. Larger meals would
suppress appetite for much longer than smaller meals. For example,
after (over-)eating out at a restaurant a few weeks ago it took about
12 hours for my appetite to return.
- testosterone: with each ramping up of the dosage there seems to be an
initial drop in testosterone characterized by low mood and sex drive.
This effect gradually subsides. I tested my test levels after having
fully adjusted (subjectively) to 1500mg/day for a few months and my
levels were actually 15% beyond the normal range. I'm guessing the
normal range doesn't take into account regular weight lifters with low
body fat though.
Note that calorie restriction has a similar effect on testosterone
levels and that in general lower testosterone is correlated with
longer lifespans. A causative relationship hasn't been proven yet but
given testesterone's strong anabolic effect this would not be
surprising. Increased anabolism would ramp up metabolism, which
usually leads to increased wear and tear if you don't upregulate
repair mechanisms by the same amount.
Anyhow, after having ramped up my dosage to 2g recently I'm pretty
sure I'm experiencing another moderate decrease in mood and sex drive.
A month later this seems to have mostly subsided. A friend and fellow
self-experimenter ramped up the dosage to 2g a few months before I did
and has since completely adjusted on all fronts. "Best time of my
life" he says. If anything he's more sexually active now than I've
ever known him to be.
- lower body fat: my body's body fat has gradually gone down
considerably. I'm currently at about 5%, down from maybe 10% before
starting Metformin.
This reduction in fat composition happened with very little conscious
effort on my part. I haven't been doing a lot of aerobics. I haven't
starved myself or dieted. I just ate when I was hungry, which happens
less frequently.
- Inhibition of both muscle growth and muscle loss: I've been lifting
weights since adolescence. I'm in my 30s now. So I'm sensitive to how
my body performs at the gym. I like my body, and the lack of desire to
see all my muscle mass wasting away was one of the reasons (besides
debilitating hunger) I could never quite stomach CRON. Call it vanity.
Call it a quality of life issue.
On Metformin I've noticed both muscle growth and muscle loss tend to
be inhibited. I've gone to very low bad fat on what is close to a
calorie restricted diet for my weight while barely loosing any muscle
mass. At least not enough to be noticeable. If anything people comment
that I seem to be bigger now but I'm certain it just looks that way
because I have lower body fat.
I have gotten a bit weaker on the major muscle groups in terms of peak
strength and reps but not nearly as much as I would have expected.
Also, the inhibition of muscle growth doesn't prevent it. If I focus
on a specific undertrained muscle group there will be a measurable
increase in strength. But I'm certainly not getting any stronger with
the big muscle groups (e.g., bench, squats, etc.) even if I try very
hard.
From my meta-research I speculate that this effect has something to do
with Metformin's influence on the mTOR pathway.
A biochemist friend of mine has argued that the loss of strength I
have experienced is well within the range of what we could expect due
to depleted levels of glycogen in my muscles and liver brought about
by the reduction in calories. Also, I'm consuming less protein so
maybe the balance point for muscle repair after a workout is lower.
- cognitive performance: like with other negative aspects of Metformin
use, I experienced an initial decrease in performance following a
ramp-up in dosage followed by a gradual return to normal after a few
weeks. The effect was most dramatic for a week or so after I increased
the dose to 1500mg/day.
I felt anxious, had trouble concentrating, kept forgetting things
(e.g., names and words on the tip of my tongue), repeated pointless
behaviors (e.g., opening the same empty cupboard over and over looking
for a lost item), failed to perceive objects that were right in front
of my eyes - which led amongst other things to an embarrassing fridge
incident. I also had a harder time expressing myself. Humor in
particular seem to be beyond my grasp.
That freaked me out a bit and I was worried I might be experiencing a
form of mild hypoglycemia but a blood test showed my BG to be in the
normal 75-85mg/dl range.
Eventually all of these symptoms subsided completely and I returned to
full cognitive performance. As far as I can tell. From my
meta-research I speculate that Metformin somehow temporarily reduced
my brain's ability to metabolise sugar. I tested normal levels of
sugar, but it felt like I was mildly hypoglycemic because my brain
cells were producing less energy with it. Perhaps the mechanism of
adaptation was the mitochondrial biogenesis I've read Metformin can
trigger. Wish I knew for sure.
- Body temperature: average waking temperature seems to have gone down
about 1-1.5 degrees Fahrenheit. Within the reference range for CRONers
but a bit on the high side for a CRONnie.
Not surprising considering I actually am restricting my calories,
though not deliberately.
- Blood pressure has gone down somewhat, mostly my diastolic though the
effect doesn't seem to be dramatic. At the Dr's office I last tested
110/58. Testing at home it's usually a bit lower (e.g., 95-105/45-55),
but that depends a bit on how relaxed I am. For anyone that thinks my
BP is too low please note that I am not prone to fainting.
Before Metformin my BP was closer to 110-120/70-80.
- Lipid levels: LDL has gone down from 81 to 61. HDL has gone up from 50
to 60. Triglycerides have gone up slightly from 41 to 57 (I suspect
this is due to increased lipolysis)
In my experimental group not everyone seemed to react the same as I did.
I advised everyone to do regular bloodwork to test how Metformin
effected their bodies in particular. For safety and of course because it
gave us more data to work with.
Gastrointestinal discomfort and a feeling of exhaustion caused one of my
friends to drop out after about a week doing just 500mg/day but most
people barely noticed the gastrointestinal effects and it seems to be
mitigated by increasing fiber intake. The initial tiredness and loss of
mood which gradually subsided seemed to effect males more than females
but this is just my impression.
Nearly everyone experienced a dose dependent reduction in appetite and a
consequent reduction in calorie intake and body fat composition but
before anyone gets any funny ideas I'd like to clarify that Metformin is
certainly not a magic weight loss pill that allows you to eat whatever
you want and still lose weight. When I dropped my dose to 1000mg/day and
ramped up my calorie intake I gained body weight (mostly muscle but also
a bit of fat) pretty quickly (3-4kg with a couple of months). A more
extreme test case was a female friend that suffers from an eating
disorder that gradually ramped up to 2000mg/day. Though her body weight
stabilized and her body fat composition changed somewhat (patterns of
fat deposits seems to have changed), her weight was not dramatically
reduced in the months when she didn't have her eating disorder under
control. Her bloodwork (blood glucose, lipid levels, etc.) did improve
significantly though. With her eating disorder under control, (mostly)
eating when she was genuinely hungry she experienced a gradual loss of
weight however.
Of course I don't have as good data for the others in my experimental
group as I do for myself. Note to anyone interpreting my personal
anecdotal experience that I may be genetically predisposed to have a
better than usual response to Metformin. According to 23andme I have a
GG genotype at rs4585:
"In this study, researchers examined metformin response in 3,920
individuals of European ancestry with type 2 diabetes. A positive
response was defined as achieving an HbA1c level below 7%. The
researchers found that individuals with the GG genotype at rs4585 (which
is equivalent to the SNP reported by the researchers) in the ATM gene
had 1.35 times higher odds of having a positive response to metformin
treatment compared to individuals with the GT genotype, and individuals
with the TT genotype had about 0.75 times the odds of having a positive
response."
Just another datapoint to those trying to evaluate my anecdotal, non
double blind, perhaps even blatantly unscientific and irresponsible
underground experimentation with a prescription drug. I wish I had a
billion dollars lying around, plus FDA approval to do a double blind
study on healthy human subjects (hardy har har!) but we have to settle
on making the most with what we have.
In any case, if it isn't clear, the sum of my meta-research and
experience leads to me to believe that Metformin is a woefully
underused, powerful health enhancing substance that can make wonderful
contributions to one's quality of life (once you get used to it) and
most likely length of life. Even if it doesn't increase maximum lifespan
like it does in many animal models, there's good reason to believe it
would improve median lifespans significantly if consumed by the general
population. It's also remarkably safe in clinically effective doses, widely
available and has a very respectable history of use.
PS: I'm posting pseudo-anonymously to avoid obvious undesirable sources of
attention. Unfortunately the first amendment doesn't hold much weight when it
comes to this sort of thing. Please respect my privacy!