Ordinarily I'd have left this thread where it was. Particularly given that the OP has decided it's not a great idea.
Unfortunately on this particular topic though: details are everything.
I'm going to try my best to not launch into some or the other thesis on the topic though i.e. been there and did that last year already.
Let me begin by clearing something up in my own post above on this topic. Bear in mind that my research and experimentation on this particular topic was in the interests of science, debunking of some myths posted around these parts and others, interest in patch construction and delivery mechanisms, and testing the efficiency of extraction methods. Point being: the results were never intended for general use (as ridiculous a statement as that sounds).
I mention the above because of my reference to extractions using Methanol and the few drops to which I referred to. By no means was I, nor am I, advocating that somebody uses Methanol to extract and makes a shooter or shot or cocktail of Fentanyl in Methanol. Methanol is a fascinating substance in and of itself but that's another entire topic of course. Suffice to say here that Methanol is extremely toxic to humans (more so than in other primates) because of what it metabolizes into in the human body. It can cause all manner of ills ranging from intoxication to blindness (temporary or permanent) to death (and an uncomfortable one at that) and starting with relatively low quantities (in the order of millilitres) (although that depends on a number of factors and which again are beyond the scope here).
Given the above it's probably best to ignore my reference to a few drops of Methanol. I cannot edit and remove the information as I've been quoted already. Suffice to say: my reference to a few drops of Methanol being used sublingual was at concentrations ranging from the sublime to the ridiculous i.e. 0.84mg/ml to 8.4mg/ml (not typos i.e. milligrams of Fentanyl per millilitre of Methanol). Obviously at lower concentrations: the Methanol would cause more harm and have more intoxicating effects than the Fentanyl itself. And obviously at the top of the range: it takes only a drop or two sublingual to take you from zero to hero to nod (and everything else extremely unpleasant in-between). And while that may sound appealing to some: I assure you it ain't.
Sorry but I had to get that (the above) out of the way in true interests of harm reduction.
Moving on...
Legitimate brand name patches will always have the total amount of Fentanyl, in milligrams, contained in a patch, printed on the packaging and on the leaflet. It's a legal requirement (FDA). This information is also easily accessible on the Internet.
In this particular case and assuming a Durogesic®/Duragesic®: a 50µg/h patch contains 8.4mg of Fentanyl in total. Be careful with this though i.e. it is manufacturer dependent. Some patches contain far more than others.
Patches are usually indicated to be worn or applied for 72 hours (3 days) but will usually contain enough Fentanyl to maintain a constant delivery for 168 hours (7 days). Long story but there's a good reason for this i.e. highly dependent on the manufacturer, type of delivery system or matrix (they're not all equal and the same), etc. Specifics aside (has to to with kinetics if you wish to go down this rabbit hole): it's obvious as to why there are warnings in regard to the correct and safe disposal of these patches.
It's also obvious that one cannot take the 50µg/h rate, multiply by 72 hours, and assume that's the total amount of Fentanyl in the patch. Far from it and probably one of the reasons why so many fuck up with these things. Assuming a Durogesic®/Duragesic® 50µg/h patch: 50µg/h x 72 hours gives you 3.6mg right? Well as noted above: that's way off of the mark. Everything being equal (delivery rates vary and depend on various factors e.g. body temperature): there still remains 4.8mg of Fentanyl in said patch after a 72 hour application (which as noted is the norm and if used as indicated and directed by most manufacturers and medical professionals).
There are various patches made under licence. Point here being: if you are in possession of some or the other unknown or obscure brand of patches then you'll usually find it's made under licence and it's sometimes necessary to trace the licence back to the licensor or patent holder in order to ascertain exact details of the patches. Be aware that counterfeit patches do exist and needless to say therein lies a potential huge risk factor and for very obvious reasons.
Fentanyl is a freestanding base while the active forms of Fentanyl exist as salts e.g. Fentanyl Citrate. Patches can contain both. The base is insoluble to slightly soluble in water but soluble in alcohols. Only the salts are soluble in both water and alcohols.
There is indeed a difference between DIA ("Drug In Adhesive") patches and polymer matrix patches. Some may say it's semantics but it's not. Note that all information posted here is NOT in reference to the old, and no longer available, gel reservoir type patches.
Any questions thus far?
Now...
There are reports of patches being steeped i.e. heated or boiled. The caveats here being that a) heat degrades Fentanyl and b) there's a possibility of melting the backing and the glue (both dependent on the amount of heat applied of course). Extraction efficiency is questionable though i.e. those that get up to such antics are usually steeping more than one patch to begin with. And it stands to reason that the strength of the brew cannot be accurately determined.
Most, if not all, harm reduction sites will advocate the heating of small pieces of a patch in purified water and citric acid (for IV anyway). However: ingestion of the same will have an effect (dare I say a more forgiving than IV though). Once again: extraction efficiency is questionable and the results can vary widely.
And the above, ladies and gentlemen, boys and girls, is a brief summation of last year's research on the topic!
It was at least a 10 page thread so thank your lucky stars that I'm able to summarize the same and well over a year later and from memory!
Now I am going to hand to you the (hidden?) BL keys to the Fentanyl patch kingdom. Ironically the very thread that brought me here in 2019! Not something that you could not have found yourselves of course (UTFSE). But it's fallen off of the radar. And while, at the time, it seemed to have been a rather contentious issue i.e. much debate as to whether or not such details should be provided: having been around these parts now for a decent amount of time I am definitely of the opinion that it's solid harm reduction advice. Fact of the matter is that of late, and in spite of my believing that this practice has gone out of vogue, I've seen quite a few threads on this topic being started. People are out there doing it so better they know what they're doing is my point.
Below is a link to THE post that's worth its salt on said thread. But feel free to start at the beginning of the thread i.e. there's piles of information (and misinformation) on said thread.
Needless to say I tested all solvents and alcohols mentioned on said thread as well as other methods detailed anywhere that the same can be found. Methanol is the only one that ensures a 100% extraction. From a pure harm reduction point of view: I'd have to say it's better to be able to quantify and be sure of the efficiency of the extraction rather than have to make assumptions.
Now that I've re-opened Pandora's Box on the topic note the following in reference to said thread and post:
You do NOT end up with powder or crystals after evaporation. While I've no reason to question the OP's outcome AT THE TIME (2013): the delivery mechanisms and adhesives etc. have been revisited time and time again by the manufacturers since so as to ensure that this practice and its outcome is all but impossible to achieve. What you will end up with after evaporation is an amount of Fentanyl combined with some glue residue and a trace (safe) amount of Methanol. This can be re-dissolved using purified water, citric acid, and ethanol as is described in the referenced post. Of utmost importance is the calculations for the titration method used i.e. don't get it wrong and make sure you're all too familiar with everything else I've noted above with regards to totals etc.
Worth noting that in spite of my noting earlier that the post on the link below is THE post on the thread: the OP actually got the total amount of Fentanyl wrong i.e. just made the assumption that a 75µg/h patch contained 7.5mg of Fentanyl. A dangerous assumption and mistake to have made (although in fairness it's quite possible that back then it was not mandatory to specify the total amount of Fentanyl in a patch). But the titration method, logic, and calculation is sound. Might also be worth noting that the OP was last seen a month after said post and never again.
would this extraction work with the Mallinckrodt patches? I have a 75mcg/hr Mallinckrodt patch that i want to extract and coat either tylenol pills or Percocets to then crush and snort but had heard that there might be something different with the Mallinckrodt patches that might make certain...
www.bluelight.org
So much for no thesis on the topic! Sorry! Did my best to summarize without sacrificing detail or being vague i.e. with this shit "the Dev6il is in the details" as they say in the classics!
In closing: I'm not advocating any of this. What comes out of these patches is potent as hell and they're better used as indicated. And as I'm sure is blatantly obvious: there's a fair margin of error possible especially if the intention is to IV (but don't be fooled either i.e. sublingual or ingestion can also have its dire consequences).
One last piece of advice (and as has been noted already here I think): always assume that you're dealing with a 100% extraction efficiency no matter what and based on the as stated, by the manufacturer, total amount of Fentanyl in a patch. If the same is not available or not stated on the packaging then don't take a chance nor try and guess nor try and calculate.
Oh and one other little nugget that's rarely mentioned: Naloxone has a much shorter elimination half life than Fentanyl (true story). It's but one of the reasons why sometimes multiple administrations of Naloxone are required to bring somebody back from the brink of a Fentanyl OD.
For what it's worth: I'm always conflicted when posting about this shit hence my not having jumped on any of the other threads that have started over recent months on this topic. Also the main reason why I deleted months and months of legit work and research here last year. I guess my point being is that if this is not considered harm reduction and considered to be more of an enabling nature then feel free to edit or delete (although it did take a good few hours this one! 
) (but no fucking warning points i.e. posted with the best of intentions I assure you! ). I just saw this thread getting a bit of traction so figured maybe it'd be a good thing to put some of this stuff out there again and for the sake of clarity.
The above being said: "TLDR" at your own peril if for some obscure reason one decides to go down this path! It's one helluva lot of trouble, not to mention cost, for very little, and short lived at that, reward (and even the reward part is debatable especially if you factor the risks into the equation).
