Taking hormones to stimulate milk production in the woman: Will she become a mother through breastfeeding thereby and will her husband become a father?

The majority of scholars think that the woman’s milk that has
consequences does not necessarily have to result from intercourse with her
husband (and resulting pregnancy) or from giving birth; rather if she takes
something to stimulate milk production then breastfeeds a child with that,
this infant will become her son through breastfeeding. Hence they did not
rule it out if a woman who is a virgin who has never been married before
breastfeeds a child; she becomes a mother through breastfeeding. This is the
view of Maalik, ash-Shaafa‘i and Abu Haneefah, and was regarded as more
correct by the Hanbali scholars al-Mardaawi and Ibn Qudaamah. 

In order for him to become a son of the woman who breastfeeds
him, it is stipulated that she should breastfeed him five times, and that
should be when the child is two years old or younger. 

Muhammad al-‘Utbi al-Maaliki (may Allah have mercy on him)
said: And I heard him –i.e., Imam Maalik – when he was asked about a woman
who takes herbs that stimulate milk production, then she breastfeeds with
it: does this breastfeeding create the mahram relationship? He said: Yes,
that creates the mahram relationship; is it not milk? He said: Yes. He [Imam
Maalik] said: Then the mahram relationship is established by that. 

Muhammad ibn Rushd al-Maaliki (may Allah have mercy on him)
commented on that: 

His comment — that if the woman stimulates the production of
milk by something that she takes then breastfeeds with that milk, then it is
milk that creates the mahram relationship — is like what is said in
al-Mudawwanah: The milk of a virgin girl creates the mahram
relationship; the milk of a woman creates the mahram relationship in all
cases, based on the apparent meaning of the words of Allah (interpretation
of the meaning): “Forbidden to you (for marriage) are: … your foster
mother who gave you suck, your foster milk suckling sisters,” [an-Nisa’
4:23]. It does not specifically mention a woman who has a husband to the
exclusion of one who does not have a husband.

End quote from al-Bayaan wa’t-Tahseel by Ibn Rushd
al-Maaliki, 5/153 

Shaykh Muhammad
ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) said: The words “and
one who is not pregnant” mean: if a woman breastfeeds a child without having
been pregnant. This happens a great deal: if a child cries, a woman comes
along who has no milk and is not married, and she gives him her breast in
order to quieten him, and the sucking stimulates milk production. If he
breastfeeds five times or more, does he become a son to her? The author said
no, because that came about without there having been a pregnancy. But this
reason is not sufficient to prove his point. The correct view, which is held
by the three imams, is that it does create the mahram relationship; if the
child breastfeeds from a woman five times, then he becomes a son to her,
whether she was a virgin or beyond the age of childbearing or had a husband.
The evidence that it established the mahram relationship is based on the
text and rational evidence. 

The textual
evidence for that is the general meaning of the words of Allah
(interpretation of the meaning): “Forbidden to you
(for marriage) are: … your foster mother who gave you suck…” [an-Nisa’ 4:23].
And there is nothing in the Qur’aan or Sunnah to stipulate that the milk
should be the result of pregnancy, so the general meaning of the text still
stands. 

The rational
evidence is that the wisdom behind the milk establishing the mahram
relationship is the nourishment of the child thereby. If the child is
nourished by it, then the reason for it creating the mahram relationship has
been established. With regard to the verse (interpretation of the meaning)
“The mothers shall give suck to their children…” [al-Baqarah 2:233],
what it refers to what the mother should do of completing the term of
breastfeeding. So the correct view is that a woman’s milk creates the mahram
relationship whether it is the result of pregnancy or otherwise. So the milk
of a virgin creates the mahram relationship, and the milk of an old woman
who has no husband and is past the age of childbearing creates the mahram
relationship.

End quote from
ash-Sharh al-Mumti‘ ‘ala Zaad al-Mustaqni‘, 13/440, 441 

See also the
answer to question no. 118709. 

Based on that,
if a woman takes medicine or eats beneficial foods that do not cause harm
and that stimulate milk production, then she breastfeeds a child with it
five times and the child is two years old or younger, then he becomes a son
to her through breastfeeding and the breastfeeding establishes the mahram
relationship which makes marriage haraam and makes it permissible to be
alone together or to look at one another and to be a mahram in the case of
travel. But it does not establish ties of lineage or obligations of
maintenance, or rights of inheritance. 

It should be
noted that the husband of the woman who breastfeeds in this case will not
become a father through breastfeeding, because the milk did not come from
him, so it is permissible for his sons from a wife other than the one who is
breastfeeding to marry the daughter who was breastfed by that wife and it is
permissible for his daughters from a wife other than the one who is
breastfeeding to marry the son who was breastfed by that wife. 

In al-Fataawa
al-Hindiyyah, by a group of Hanafi scholars (1/343) it says: A man
married a woman who never bore him any children, then she produced milk and
she breastfed a boy. The breastfeeding was from the woman without her
husband being connected to it, so the children of this man from any other
wife did not become mahrams to the boy. End quote. 

In Mughni al-Muhtaaj
by ash-Sharbeeni ash-Shaafa‘i (3/420) it says: If a virgin produces milk and
she gets married and gets pregnant from her husband, the milk belongs to her
and not to the husband so long as she has not given birth, and if she
breastfeeds an infant, then her husband is not a father to that child. But
if she gives birth to his child, the milk after she gives birth belongs to
him. End quote. 

The ruling will never
differ concerning the husband of the breastfeeding woman with regard to
practical shar‘i rulings having to do with looking or being alone with (the
one who was breastfed). He is the husband of the mother of the breastfeeding
child; if the one who is breastfed is female, then she becomes his
stepdaughter and it is haraam for him to marry her and the same rulings
apply to him as to a father through breastfeeding in this regard. 

It should also be noted
that the word “adoption” mentioned in the question is not used in the sense
that is forbidden in Islam, which is when the child is attributed to someone
other than his real father. Rather what is meant is taking care of an orphan
and looking after him. Hence we prefer not using this word in this sense
because of the confusion it may create. 

See also the answer to
questions no. 10010 and
126003. 

And Allah knows best.